Hi, I have tried applying Live wallpaper from 4kapp and it worked totally fine. Do note not all third party app will work as intended. I am on latest .122 software version.
I'm also having problems with live wallpapers. I dl'd the Mi 10 live planet wallpapers from XDA but after applying the wallpaper, after a period of time, it would just revert back to the original ROG one. This doesn't happen on my OnePlus 6T.