Same here.
I'm using Xcode Version 13.1 (13A1030d) on Big Sur 11.5.2 and it hasn't been working on the previous version.
For example, when I type "@Pu", the expected behavior is showing an option "@Published" below the "@Pu". However, it doesn't give any suggestion and react nothing. All of the property wrappers are the same.
Rarely it works outside of the class or struct area, but most of time it doesn't work.
I tried cleaning up the project, restarting the Xcode, rebooting my laptop, and cleaning other removable cache data as well.
Still doesn't work and don't know how to fix it..