Hi,
Thank you for writing to us.
It appears that some other third-party plugin is causing such an issue and it’s working fine in our test environment.
Here is what you can do to check:
1. Please try switching to another theme, like Twenty Twenty-one
, and check whether the issue persists or not. If not, then it is the theme that is causing the error.
2. Deactivate all plugins temporarily except WPDM and see if that solves the problem. Then, activate plugins one by one to see which plugin is causing the problem.
3. Try one more time after clearing your browser, website, and CDN caches if you have any. You may temporarily disable the caching plugin for testing.
This is a general debugging process that all WordPress support teams perform to find 90% of the problems.
Please let me know how that goes. I will be happy to help with any further assistance you might need.