"No Connection" prevents any games from downloading

[askAvoid]

Your system information

• Steam client version: Latest
• SteamOS version: Latest
• Opted into Steam client beta?: No
• Opted into SteamOS beta?: No
• Have you checked for updates in Settings > System?: Yes

Please describe your issue in as much detail as possible:

Ubuntu 24 LTS and Steam installed via Flatpak.

Download window says "NO CONNECTION" and nothing downloads, even though the Steam client can be used to browse the store, community pages, etc.

There is literally not a single other message, error or otherwise useful indication of what's wrong.

Steps for reproducing this issue:

1. Build a new PC
2. Install Steam
3. Try to download some games

[kisak-valve]

Hello @askAvoid, any relevant hints would probably be in <steam_install_folder>/logs/content_log.txt.

[askAvoid]

Thank you for the suggestion, unfortunately there isn't anything useful there during the event:

AppID 221100 scheduler update : Priority First, not played for 4010852 seconds, update disabled for 0 seconds
AppID 221100 state changed : Update Required,Fully Installed,Update Queued,
AppID 221100 state changed : Update Required,Fully Installed,Update Queued,Update Running,
AppID 221100 update changed : Running Update,
AppID 221100 update canceled : No Details (No connection)
AppID 221100 update changed : Running Update,Stopping,
AppID 221100 update changed : None
AppID 221100 state changed : Update Required,Fully Installed,Update Queued, (No connection)
AppID 221100 state changed : Update Required,Fully Installed, (Update delayed for 30 secs)
AppID 221100 scheduler finished : removed from schedule (result No connection, state 0xe) 

Restarting Steam always restores network connectivity, then it goes in and out seemingly at random while running. I also have trouble uploading screenshots and cloud sync/saves - it takes several attempts (up to 5 or 6) to get them through.

[askAvoid]

@kisak-valve Hello?