SUMMARY

I get this bug whenever I try to load and save files remotely using Kate and KDevelop. Since I think it is a kio problem, I am posting it here.

At first I had problems with loading files from remote server (sftp and fish), I was constantly getting messages "Malformed URL .", and only after re-trying, by hitting the F5 many times, after some random N attempts the file would load.

After that, I thought it would be a good idea to try to update the whole KDE. 

After the update, files are being loaded, but I can't save any changes, even if I try to save the file locally, on my disk, and not just on the remote server.

STEPS TO REPRODUCE
1. Open some remote location in Dolpin, using SFTP (it is a connection to a SSH server using keys, default port is changed)
2. Select a file on the remote location, and try to drag and drop it to the KDevelop or Kate
3. "Malformed URL" dialog will appear many times, but after you try to re-load it, it will eventually, after 100 attempts load the file
4. Edit changes, try to save the thing, it won't work from the first time.

OBSERVED RESULT

1) Files not saved nor loaded at the first attempt. "Malformed URL" message dialog appears (the URL is valid)


EXPECTED RESULT

1) Files to be loaded from the remote location, without the dialog box, from the first time, not after 100th time.
2) Ability to save the files locally (only in Kdevelop).



SOFTWARE/OS VERSIONS
OS: Ubuntu 19.10 
KDE Plasma version: 5.18.3
KDE FrameWorks version: 5.67.0
Qt Version: 5.12.4
Kernel Version: 5.3.0-51-generic
CPU: AMD Ryzen 7 3700X
Motherboard: ASUS TUF Gaming x570 plus
KIO version: 5.67.0-0ubuntu1~ubuntu19.10~ppa2


ADDITIONAL INFORMATION


I've enabled back-ports repo in Ubuntu, in order to update the KDE to the latest available version in the repos. Updating KDE did not help.