Randomly got red Low FPS warning and was kicked for inactivity?

I was in the middle of my second match of the day, everything was going well. Then I started to notice some minor stuttering, but that passed.

Then a few minutes later I suddenly got a red Low FPS warning and it felt like the game was going in slow motion. Got a few seconds of yellow Low FPS warning before it went back to red.

And despite me constantly being in movement and attempting to keep playing, I was suddenly kicked from the game due to inactivity.

I probably lost the progress I made during this match as well.

My PC have no issues with running the game, especially on the settings that I have in use so I can't quite understand what caused this? I've never experienced this before.

All my previous issues have been packet loss and latency related because of server issues, but this seems to have improved after the latest larger update.