This could be a third party plugin which is causing code conflicts.
- Please deactivate all installed 3rd party plugins.
- Delete browsers cache
- Re-save permalinks.
If it does not work only then share your wp-admin url and credentials in a private reply so that i can look into this matter.
Tip: For better support always share a screenshot:
Please provide proper screenshot, use https://prnt.sc/ to upload and share url of the screenshot.
If you want to send us a video of the issue, use https://screencast-o-matic.com/ to upload and share url of the video.