Hi @Henrinawrocki thanks for the update.
I think the smart thing to do before filing N-400 is to file FOIA request asking for ALL immigration files. In the response, if you see your request and documentation about divorce in the file - it's pretty safe to proceed with naturalization.
If you don't get any info about divorce in FOIA response, as if they never took it into consideration, then I'd lawyer up and proceed very carefully with N-400. You may need to prove you sent the docs etc etc and it would not be a simple case.
Good luck!