Ggjj, do you have a look at this problem? Does caching cause cross domain problems?

use vue2 Wrote a pc Rear pipe system
The back end uses php Written
Cross domain processing has been done before and after the release
Before deployment , No matter in the test address or the real address request, there will be no cross domain problems , Never appeared
But after deployment , Here's the problem , The request to visit the website will report cross domain problems , When I clear the cache and continue to re request, it will return to normal . Then after a while, the request will appear cross domain .
I don't know where the problem is , There are few online related problems , The reason is nowhere to be found
The front and rear end personnel don't know how to solve , Please understand ggjj Stretch out your hand , Be deeply grateful