Sudden FPS drops, ALT+Tab fixes (then drops again)

Is anyone experiencing a sudden drop in FPS, for example, in town or in their own hideout?

I started noticing this maybe 5 days ago, even though I never really touch any settings once they are fine for me. It just happens, the game will run normally for a couple of minutes and then the frame rate just drops from stable 60 to 30 or sometimes 20.

An ALT+Tab and then back to game "fixes" it for a couple more minutes. Rinse and repeat.
At some points during actual game play it drops good, in areas that never really had any problem.

Does anyone experience the same or similar?


* UPDATE:
Playing in windowed mode doesn't seem to cause the issue. So it is mostly a full screen plague.

I usually play at windowed mode, same issue. Fps drops from 60 to 20-30.

Backupp, thanks for your feedback. I just wanted to make sure I wasn't alone on this.

I see people having FPS drops for various reasons but many posts are pre-2017, so I don't know what is the possible cause. First I thought it could be something related to graphics card or CPU, but I haven't changed anything in months and the few other games I play (Starcraft 2 and some Zuma/Bejeweled 3 here and there) work fine.

It also didn't happen until maybe 5 days ago, and I don't remember any PoE patch from last week.