Hi,
Welcome to the community!
Analysis uses SCM blame data to determine what was changed in the PR. So if these PRs are truly being analyzed as PRs, then the question is why the SCM blame data isn’t showing what you expect it to.
In previous instances of “way too much shows up as new” the problem has been automated linebreak/whitespace “correction” processes. I.e. automatically change all tabs to spaces before/during commit. Altho, to be honest, I haven’t seen that one in quite a while.
Can you share your analysis log?
The analysis / scanner log is what’s output from the analysis command. Hopefully, the log you provide - redacted as necessary - will include that command as well.
This guide will help you find them.
Ann