Dear respected Schmidtler_408,
Good day! Thank you for posting to Microsoft Community. We are happy to help you.
As per your description and error message, I believe the error message occur due to website link address not completed. Based on my test result I also get the same error in hyperlink column if the address link in not correct. Here is screenshot for your reference.
First may I know did you add website link manually in a Microsoft list hyperlink column? if you add file document link in your hyperlink column in SharePoint/Microsoft list, and does it will return errors as well?
If possible, could you please confirm are you able to access website via direct link in a browser, it will help for us to narrow down your problem.
Also, may I know does this problem is happened to specific Microsoft List? If possible, could you please create a new list and add the hyperlink column and verify the result with us.
Appreciate your patience and understanding and thank you for your time and cooperation.
Sincerely,
Waqas Muhammad