I have 2 different CSGO accounts, and I noticed that whenever I switch them, the software doesn't record the new account.
In order to have it record, you have to close the software again, close the game and then reopen software and game..
Kinda annoying and just noticed I lost dozens of hours of recording to this..
I just had us check and it definitely recorded both sessions after swapping Steam accounts.
Did you jump into a different CSGO type (ESEA, FACEIT, etc) in the second match?
If you want, we can try to investigate this further for you.