it's interesting that you can't pass the value directly. I recreated your scenario and observe the same behavior. One option is to create a calculated field which is a representation of the value and then pass this as part of the action URL. See screenprints.
Include the calc as part of the action:
Test the link:
Perfect! thank you for your help on that.
I had one more issue with the "Missing fields on <source sheet name>" warning in the URL Action after applying your trick but I manage to resolve using the following article (just in case someone stumbles across the same problem in the future).