Regarding FPS drops during Pro Club play
When playing Pro Club Drop-In, the FPS drops below 15 during the pre-match loading phase. Up until that point, the FPS is perfectly fine, running at 144 FPS. Once this issue occurs, the FPS remains below 15 even on the menu screen.
Lowering the display settings didn't help. In fact, there's an underlying issue where screen mode and graphics settings in the display settings don't save. I have to repeatedly reset them and restart the game.
Then, when I finally think the settings saved and try to play Drop-In, the FPS drop makes it unplayable. Another restart.
I've played this game for about 6 hours, but after dozens of restarts, I've only managed to play two matches properly.
My PC meets or exceeds the recommended specs, and I played FC25 without any issues. In fact, the menu screens and other interfaces run smoother on FC26.
Looking at Reddit, I saw several people suffering from the same symptoms. Just for reference.