The popping scenery tiles bug seems to be back in the latest beta build 1.6.13.0. This was an old bug back from FS2020 that was fixed before. There is a circle of tiles that appears as the camera or plane is moving over the scenery.
From my testing, it only happens all over Japan in areas without PG and also around Shanghai. Have not noticed it anywhere else so far.
Clip of the issue taken around Shanghai : Watch SU4Beta popping tiles | Streamable