I'm seeing the same behaviour as listed in this Issue: https://lab.civicrm.org/dev/core/-/issues/528
However, I'm running 5.33.1 and WordPress 5.6. The fix listed there appears to have been superseded at some point so I'm not sure if I'm having the same problem or this is a new problem?
This isn't happening on the https://wpmaster.demo.civicrm.org/ site, which is currently running 5.35.alpha1.
Nothing is appearing in my ConfigAndLog files and this is what I see in the browser console:
Status 500 Internal Server Error VersionHTTP/2 Transferred710 B (338 B size) Referrer Policystrict-origin-when-cross-origin