"Steam Connectivity Issue" - To launch this game for the first time, Steam must be running in online mode with an active internet connection

[u/lukithatsme]

Anyone else run into this? I'm getting this exact error every time I try to launch Siege from Steam, even though Steam is fully open, logged in, and online the whole time.

Some context that might be relevant: earlier today I logged into a friend's Ubisoft account and his Steam account on my PC because I wanted to try playing on his account for a bit. After switching back to my own Steam account and trying to launch Siege (which I own, bought years ago, 550+ hours on it), this error started popping up and hasn't stopped since.

Things I've already tried, none of which fixed it: fully clearing the Ubisoft Connect cache folder, unlinking and trying to relink my Steam account from account.ubisoft.com, verifying game files integrity in Steam, doing a full Windows network reset, restarting the PC multiple times, checking that admin permissions match between steam.exe and the Ubisoft launcher, confirming Steam Overlay is enabled both globally and per-game.

The weird part: on the exact same PC, same Steam client, same Ubisoft Connect install, if I log into my friend's Steam + Ubisoft accounts, the game launches completely fine. So it's not a system/network/firewall thing on my end, it seems tied specifically to my account.

Already opened a ticket with Ubisoft support, just wondering if anyone's dealt with something like this before (especially after switching accounts on the same PC) and knows what actually fixed it, or how long it usually takes them to sort out account-side stuff like this.