I found a solution that worked for me - closing all Visual Studio windows, deleting the .vs
folder from the project, and reopening it while allowing background tasks to finish before interacting with the project again.
Although I now have all the suggested CSS, there are still occasional failures without clear reasons. So, I'm keeping this question open in case there's a way to increase IntelliSense limits.
[UPDATE] I also reported this issue on the Developer Community and it appears to have been fixed in VS 2022 17.1 Preview 3
. While I haven't tested it yet (waiting for stable release), since no other solutions were found, I will mark this question as resolved.