Trouble keeping onine/profile connection

[chsck]

Returning to the game recently I began having trouble with staying connected once I leave the main menu.
When launching the game it displays i'm logged in and te4.org later confirms that there was a login.On steam version it still has all my unlocks and donator features (possessor, my beloved psionic), but loading or creating a character displays a message "Online profile disabled due to no profile active". This means no in-game chat and no profile updates on te4.org (it doesn't notice new unlocks and doesn't update characters on the site). Quitting to the main menu reveals I'm not logged in anymore. Attempts to log back in fail - "Steam client not found".
Using te4.org version has similar results (AND doesn't let me use Exploration/Possessor).
Thing I tried: disabling firewall, reinstalling both versions, clearing T-engine folder, launching from admin, using phone connection instead of wi-fi.
Attaching debug log files, but can't find anything coherent about error messages there. Please help me understand what's wrong.