Thanks for posting.
From your description, it sounds like your camera will require service to correct this issue.
You may set up the repair of your camera at this site: https://www.usa.canon.com/repair. When accessing our site, we recommend the use of updated versions of the Chrome or Firefox browsers.
Once on our site, click on "Request Product Repair", the follow the instructions that follow.
Maybe you knocked a screw or screws loose from the fall? Have you tried to tighten the tiny screws you can see? I would try that first in an attempt to avoid a costly repair bill. Unless you purchased accidental damage protection any repairs for that most likely will not be covered under warranty.
09/26/2023: New firmware updates are available.
08/18/2023: Canon EOS R5 C training series is released.
07/31/2023: New firmware updates are available.
05/31/2023: New firmware updates are available.
05/18/2023: New firmware updates are available.
03/30/2023: New firmware updates are available.