Yes, im running Win10 (specifically quite dated 21H1 build with forcibly disabled updates).
As for OBS it was 29.1.3 (the last one to support Sandy Bridge's Quicksync hw-enc. Quick googleing suggested OBS 29.x.x weren't the most trouble-free release at all, and general recommendation was to downgrade to a 28.1.2 or even 27.2.4 if games bugs out, which i happily obliged. Got installed 27.2.4 as the last 32bit OBS (to be as failsafe as possible), and it was smooth sailing for the whole evening afterwards, not a single `booted as a cheat` for me. Quite possible 29 got app hooking somewhat wrong. Next time will try 28.1.2, for science's sake.