Intersting is that on my desktop the focus session was not started, but checking on on my android, it was running, but I didnt started it
See, I started a task here

when looking at the notification I saw that I was at session 2 of 4

And when looking that the focus session, it was running even that I didnt tell it to start.

I'm still letting it run to see if it will stop at 1h40, but it could be the reason for the problem?
If I remember right, in the morning I didnt have a problem, because I didnt install the software on my phone, at afternoon, I installed it on my android, and also enabled the sync via google drive. That was when I had problems.
I also dont remember changing any option about the focus session. Is it possible that the default options of focus session on mobile is causing this problem? It looks like it might be the real issue. I'm still letting it run on both desktop and mobile (without sync) to see if one of them will stop automatically and when.
I think I got it. I had the automatic pause and continue session enabled on my settings, and by default it seems that working hours tracks the times and warns about when I go over the time on the session focus. so it seems that if I have the automitc pause and continue enabled it could stop automatically.
I disabled it on the desktop and I'm running to see if it will go over 1h40 and on mobile I left it enabled.