Bug 512138

Here also
Opensuse TW, kdeconnect 1.34.3

Hello i'm using Manjaro Linux and KDE-Connect with Plasma,

Also on my Smartphones i use KDE-connect, there are threee:
- Samsung XCover4, Android 9
- Google Pixel 4a (4G), LineageOS 22.2 / Android 15
- Google Pixel 5, LineageOS 23, Android 16

Because i use kde connect only casually, i've seen the problem just yet.
Only randamly i got a connection to Linux or between the smartphones. After finding the setting for "Enable MDNS device discovery" the smartphone got again connections after a restart. An other problem is the connection to linux, here kde-connect 25.08.1, sometimes it seems, that the phones will be reconnected, but mostly i have to decouple them and connect them again. But unfortunately not reproducible. 

An what i don't understand, that they get connections, lost them, and randamly in the next seconds, minutes or even more, they reconnect. That would be no problem, if i can force them to reconnect but if i chose such a connection, i get a message like "System is not reachable" and i am in the net via WLAN/WiFi with the devices ...

I hope it will help somehow ... thank you very much!

if you have scenarios with which i can support you, mail me ...

(In reply to Alexandria Gaia from comment #0)
> SUMMARY
> Pixelbook Go (atlas) will not connect to KDE/Plasma desktop unless MDNA
> discovery setting is enabled.
> 
> STEPS TO REPRODUCE
> 1. Install the KDE Connect App on a Pixelbook Go.
> 2. Open the KDE Connect app on both the desktop and laptop.
> 3. Ensure both devices trust the network they're connected to.
> 4. Navigate to the "Pair new device" screen on either device and refresh.
> 5. On the Pixelbook Go, toggle the MDNS setting "on" and retry step 4.
> 
> OBSERVED RESULT
> After step 4, the devices cannot discover each other. After step 5 the
> devices can discover each other.
> 
> EXPECTED RESULT
> After step 4, the devices should have been able to discover each other. Step
> 5 should be unnecessary.
> 
> SOFTWARE/OS VERSIONS
> Laptop;
> Google Chrome	143.0.7499.11 (Official Build) dev (64-bit) 
> Revision
> 9c1108a5b2af37d00cec0595d960b3207a51cf48-refs/branch-heads/7499@{#586}
> Platform	16463.10.0 (Official Build) dev-channel atlas
> Firmware Version	Google_Atlas.11827.198.0
> Customization ID	atlas
> ARC	14340238 SDK Version: 33
> JavaScript	V8 14.3.127.4
> User Agent	Mozilla/5.0 (X11; CrOS x86_64 14541.0.0) AppleWebKit/537.36
> (KHTML, like Gecko) Chrome/143.0.0.0 Safari/537.36
> 
> Desktop;
> Linux/KDE Plasma: 6.16.12-hardened1-2-hardened (64-bit)
> KDE Plasma Version: 6.5.2
> KDE Frameworks Version: 6.19.0
> Qt Version: 6.10.0
> 
> ADDITIONAL INFORMATION
> The laptop was able to discover this desktop normally prior to the MDNS
> discovery feature deprecation.
> 
> The laptop also used to be able to discover my phone, a Pixel 10 Pro XL
> (mustang), and cannot anymore regardless of the MDNS discovery setting on
> either device.
> 
> Phone;
> Hardware Version: MP1.0
> Android Version: 16
> Android Security Update: November 5, 2025
> Google Play System Update: October 1, 2025
> Google Play Version: 48.8.07-31 [0] [PR] 829632341
> Kernel Version: 6.6.82-android15-8-gd4aed7ed470e-ab13759939-4k
> Build Number: BD3A.251105.010.E1

(In reply to Hardy Hünteler from comment #2)
> Hello i'm using Manjaro Linux and KDE-Connect with Plasma,
> 
> Also on my Smartphones i use KDE-connect, there are threee:
> - Samsung XCover4, Android 9
> - Google Pixel 4a (4G), LineageOS 22.2 / Android 15
> - Google Pixel 5, LineageOS 23, Android 16
> 
> Because i use kde connect only casually, i've seen the problem just yet.
> Only randamly i got a connection to Linux or between the smartphones. After
> finding the setting for "Enable MDNS device discovery" the smartphone got
> again connections after a restart. An other problem is the connection to
> linux, here kde-connect 25.08.1, sometimes it seems, that the phones will be
> reconnected, but mostly i have to decouple them and connect them again. But
> unfortunately not reproducible. 
> 
> An what i don't understand, that they get connections, lost them, and
> randamly in the next seconds, minutes or even more, they reconnect. That
> would be no problem, if i can force them to reconnect but if i chose such a
> connection, i get a message like "System is not reachable" and i am in the
> net via WLAN/WiFi with the devices ...
> 
> I hope it will help somehow ... thank you very much!
> 
> if you have scenarios with which i can support you, mail me ...
> 
> (In reply to Alexandria Gaia from comment #0)
> > SUMMARY
> > Pixelbook Go (atlas) will not connect to KDE/Plasma desktop unless MDNA
> > discovery setting is enabled.
> > 
> > STEPS TO REPRODUCE
> > 1. Install the KDE Connect App on a Pixelbook Go.
> > 2. Open the KDE Connect app on both the desktop and laptop.
> > 3. Ensure both devices trust the network they're connected to.
> > 4. Navigate to the "Pair new device" screen on either device and refresh.
> > 5. On the Pixelbook Go, toggle the MDNS setting "on" and retry step 4.
> > 
> > OBSERVED RESULT
> > After step 4, the devices cannot discover each other. After step 5 the
> > devices can discover each other.
> > 
> > EXPECTED RESULT
> > After step 4, the devices should have been able to discover each other. Step
> > 5 should be unnecessary.
> > 
> > SOFTWARE/OS VERSIONS
> > Laptop;
> > Google Chrome	143.0.7499.11 (Official Build) dev (64-bit) 
> > Revision
> > 9c1108a5b2af37d00cec0595d960b3207a51cf48-refs/branch-heads/7499@{#586}
> > Platform	16463.10.0 (Official Build) dev-channel atlas
> > Firmware Version	Google_Atlas.11827.198.0
> > Customization ID	atlas
> > ARC	14340238 SDK Version: 33
> > JavaScript	V8 14.3.127.4
> > User Agent	Mozilla/5.0 (X11; CrOS x86_64 14541.0.0) AppleWebKit/537.36
> > (KHTML, like Gecko) Chrome/143.0.0.0 Safari/537.36
> > 
> > Desktop;
> > Linux/KDE Plasma: 6.16.12-hardened1-2-hardened (64-bit)
> > KDE Plasma Version: 6.5.2
> > KDE Frameworks Version: 6.19.0
> > Qt Version: 6.10.0
> > 
> > ADDITIONAL INFORMATION
> > The laptop was able to discover this desktop normally prior to the MDNS
> > discovery feature deprecation.
> > 
> > The laptop also used to be able to discover my phone, a Pixel 10 Pro XL
> > (mustang), and cannot anymore regardless of the MDNS discovery setting on
> > either device.
> > 
> > Phone;
> > Hardware Version: MP1.0
> > Android Version: 16
> > Android Security Update: November 5, 2025
> > Google Play System Update: October 1, 2025
> > Google Play Version: 48.8.07-31 [0] [PR] 829632341
> > Kernel Version: 6.6.82-android15-8-gd4aed7ed470e-ab13759939-4k
> > Build Number: BD3A.251105.010.E1

Addition:
just needed a connection and to force it, i first try a restart at Pixel-4a, no difference. Second i restart Manjaro-Linux an the connection was established.

I add my comment as per the bug report request found on KDE Connect :
- KDE Connect 1.34.4 and Android 13 installed on some niche retro-console device (Anbernic RG406V) 
- - Can see my Desktop running KDE Connect 25.08.1
- - Cannot see KDE Connect 1.34.4 on my Pixel 7a / LineageOS 23-ish unless I enable mDNS discovery on RG406V.
- - - It still connects fine using manually inputting IP address (but it's out of this scope, I think)

Same on LineageOS 23.0 (Android 16) with AFWall+ application firewall, configure to allow LAN access:
https://bugs.kde.org/show_bug.cgi?id=512315

*** Bug 513002 has been marked as a duplicate of this bug. ***

*** Bug 513297 has been marked as a duplicate of this bug. ***

*** Bug 513516 has been marked as a duplicate of this bug. ***

MDNS discovery was removed in 25.12, since it was causing conflicts with Avahi. We will change the implementation (so it makes use of Avahi instead) and add it again in the next version.

*** This bug has been marked as a duplicate of bug 511914 ***

*** Bug 512595 has been marked as a duplicate of this bug. ***

*** Bug 511914 has been marked as a duplicate of this bug. ***