I am not seeing this problem.
I am wondering if it is a renovation filter and/or graphic override.
What happens when you select the drawing in the layout, right click on it and choose "open source view".
If the coverfill is missing then I would suspect reno filter or graphic override.
If it is still there then I am not sure.
Also not sure why it is affecting just the mesh coverfill and not slabs.
Make sure you have the latest update for version 20 (build 4009).
Barry.
One of the forum moderators.
Versions 6.5 to 27
Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10
Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11