I have also suddenly started facing a lot of issues with my Zenfone 8 Flip since last Friday.
First I encountered lag in shooting video. Then cellular network connection, especially any data mostly refused to work at all, I can see both the 4G and the GSM ones in the menu but not connect to them. Sometimes I get Edge or GSM and manage to make a call until it also disappears. Closing the call is hard as the screen tends to blackout.
I also have a lot of crashes and lag, especially when trying to use the camera or anything related to mobile data. Then after reading posts online of similar recent issues I tried flipping the camera and it also mostly doesn't work, the motor sometimes sounds as if it going the wrong way and says that it is blocked, but sometimes moving it with the volume buttons work.
Update: Internet started working again and haven't had a crash in quite a while. Did a lot of things, like clearing a ton of cache, and got no idea what made it work.
Though the camera is still bad at flipping. You can't use the standard flip the camera buttons in the camera app or other apps. But the manual tilting and preset angles work fine so I always have to do it manually when starting a video call or similar.