SUMMARY

I use Korganizer and Google calendar on my phone.
I can create or delete events and tasks from my phone or from Korganizer and the changes are synchronised.
After some time of use the changes are not synchronized.


STEPS TO REPRODUCE
1. 
2. 
3. 

OBSERVED RESULT
The Akonadi server appears to loose some of its runtime information, for example, authentication and is unable to log into remote accounts.  See below 'ADDITIONAL INFORMATION'

EXPECTED RESULT
Any changes to an event or task made on one device should, provided the network is all ok, synchronise all changes.

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: Linux 20.10
(available in About System)
KDE Plasma Version: 5.19.5
KDE Frameworks Version: 5.74.0
Qt Version: 5.14.2

ADDITIONAL INFORMATION

Similar issues occur with Kmail (I did log the bug) so I tried to isolate problem to Akonadi.  For example, kmail at times does not list remote account directories but display the local directories.  I have two remote accounts, one is with Google the other is specific to Australia.

Often the problems resolve themselves after running 'akonadictl restart' but the strange thing is akonadictl terminates but sit in the background logging messages to the console.  This was helpful.

Here is what I recorded along with some comments explaining what I was doing.


1)  After running 'akonadictl restart' I noticed the following message

org.kde.pim.akonadiserver: Cannot connect to agent instance with identifier 'akonadi_google_resource_3', error message: ''


2)  From Korganizer I created a new event and noticed the following error messages

org.kde.pim.akonadiserver: New notification connection (registered as Akonadi::Server::NotificationSubscriber(0x7ff62412f1b0) )
org.kde.pim.akonadiserver: Subscriber "TagCacheMonitor - 94143692156560" disconnected
org.kde.pim.akonadiserver: Subscriber Akonadi::Server::NotificationSubscriber(0x7ff62412f1b0) identified as "EditorItemManagerMonitor - 94143688818256"
org.kde.pim.akonadiserver: Subscriber "TagWidgetMonitor - 94143688055040" disconnected
org.kde.kgapi: Unauthorized. Access token has expired or is invalid.
org.kde.pim.google: Got error: KGAPI2::TaskListFetchJob(0x557304223b90) "Invalid authentication."
org.kde.kgapi: Unauthorized. Access token has expired or is invalid.
org.kde.pim.google: Got error: KGAPI2::ContactsGroupFetchJob(0x55730429ed80) "Invalid authentication."
org.kde.kgapi: Unauthorized. Access token has expired or is invalid.
org.kde.pim.google: Got error: KGAPI2::CalendarFetchJob(0x5573042ac2f0) "Invalid authentication."
org.kde.pim.akonadiserver.search: Executing search "searchUpdate-1613882173"
org.kde.pim.akonadiserver.search: Search  "searchUpdate-1613882173" done (without remote search)
org.kde.pim.akonadiserver.search: Search update for collection "DeclinedInvitations" ( 97 ) finished: all results:  0 , removed results: 0
org.kde.pim.akonadiserver.search: Executing search "searchUpdate-1613882173"
org.kde.pim.akonadiserver.search: Search  "searchUpdate-1613882173" done (without remote search)
org.kde.pim.akonadiserver.search: Search update for collection "OpenInvitations" ( 96 ) finished: all results:  0 , removed results: 0


3)  After running 'akonadictl restart' I tried to delete an event which was showing in both Korganizer and Google calendar.  I deleted the event in Korganizer and got the following.

org.kde.pim.google: Could not remove item "application/x-vnd.akonadi.calendar.event"
org.kde.pim.akonadiserver: Handler exception when handling command FetchItems on connection korganizer-48271 (0x557192b153b0) : Item query returned empty result set


If you want me to run more tests please detail what needs to be done.