You did a major move... a little more information is needed.
Did you roll out nginx on your own, or is it part of a panel setup? Did you use CentMinMod to install on a VPS?
The operands of nginx are worlds of difference between it and Apache.
Did you enable friendly URL's and not set up the correct tryfiles?
Have you checked your nginx logs? If so, do they give any clarity?
There is not simple "one click" answer to your question.
If you are REALLY wanting to use nginx... then I STRONGLY encourage you to install AlmaLinux 8 on your system (if running a VPS/dedicated server) and then grab @eva2000's CentMinMod and install it... it takes almost ALL the pain out of running nginx on a system. The ONLY weakness it has is you really have to depend on outside resources for your mail processing.