If you use git, you can try to switch to a previous commit, and then re-run the project, it may work normally. or you can modify some of the code in the project (such as comments, spaces), and then re-run the project, which works for me

I have deleted the entire Developer folder and it still doesn't work. I just modified the code in some files, and now it’s OK, wasting my entire day.

@charon1664 You can try to restart the phone or update the phone system to solve this problem,after I updated iOS14.7,it work fine