Content Type Gallery: Unexpected Error for document template

I created a document library for templates and linked it to my hub site. Then, I created a custom content type in the admin center.

After uploading a Word template to the library, I tried to associate the URL of the template with my custom content type. However, I encountered the following error:

"An unexpected error has occurred. Please try again later."

Here’s what I’ve tried so far to resolve the issue:

• Adjusted the file format from .dotx to .docx
• Shortened the URL to just the tenant address + filename + file format

Despite these efforts, the issue persists. Has anyone encountered a similar problem or have any suggestions for resolving this?