There are many reasons why you may be seeing a 404 error. One common reason is when a theme or plugin calls a flush rewrite rule. Here are a couple things you can try:
Try re-saving your WordPress permalinks:
- Navigate to SETTINGS > PERMALINKS
- Scroll to the bottom and click Save Changes
This performs a hard flush of your rewrite rules and will update your
.htaccess file. This is a plugin- & theme-agnostic solution that corrects 404 issues the majority of the time.
If you’re still having issues, try to reverse any recent changes you made on your site. Did you update a theme or plugin? If so, try deactivating the new plugin or revert to a prior version of the theme. You should also test with a default WordPress theme, like Twenty Nineteen. After reversing your changes, repeat Step 1.
If you’re still having issues, please contact support.