HTTP/2 Error: PROTOCOL_ERROR when adding Nextcloud integration

[FatherRedbeard]

Describe the bug
After installing Planify and attempting to add Nextcloud integration, receive HTTP/2 Error: PROTOCOL_ERROR error

To Reproduce
Steps to reproduce the behavior:

1. Open Planify
2. Go to Preferences
3. Select Integrations
4. Click "+"
5. Select Nextcloud
6. add server URL and login information
7. Click "Log In"
8. Observe subject error

Expected behavior
Add Nextcloud integration successfully with known good server URL and login credentials

Screenshots

Desktop (please complete the following information):

• OS or DE: Pop!_OS 22.04 LTS x86_64
• Version: Gnome 42.9

Additional context
Nextcloud instance is hosted on the same network as desktop. Other Nextcloud integrations work, including Pop!_OS built in "Online Accounts" feature.
I attempted the same function from a laptop running the same OS/DE and had the same results. Timeout/error takes over 1 minute to appear in both cases.

[FatherRedbeard]

Update:
Nextcloud instance is behind NPM
Added IP address rather than URL
This appears to allow adding the Nextcloud source, however the application locks up and needs to be forced close

• Nextcloud source appears in left-hand pane of UI next to "Meet Planify" item. (I can gather screenshot of this if it's helpful)

[oktayacikalin]

Did you try to use http://something.local or https://something.local? What does your URL look like now?

I had the situation that, after experimenting with several task apps on Android, my dataset in Nextcloud got corrupted in the sense that my subtasks had endless loops in the dependencies. Planify did not handle this and got into an endless loop as well. I had to kill it.
I exported all my lists using aCalendar+, which extracted all tasks without the loops. Then I deleted and reimported all of them using the NC calendar web UI. Of course, some tasks had to be moved around to their places, but I got rid of those loops.
Perhaps you got something similar?
Does it lock up every time when syncing?

[FatherRedbeard]

Did you try to use http://something.local or https://something.local? What does your URL look like now?

I did not. My Nextcloud instance is behind NPM also on the same network. I have a .pro domain on it that looks something like this https://nextloud.domain.pro/
This same URL works with other Nextcloud integrations including the official Nextcloud desktop and mobile apps (Linux and Android).

Right now it locks up immediately upon opening it and I can't remove or attempt any other URL. I'll try uninstalling and reinstalling to see if it lets me in the app again.