This looks more like a bug, but as per requested by the Support team here the details:
Apparently, containing special chars like : in the URL is problematic. For example, for the official Google Maps Routes API Endpoint:
"/directions/v2:computeRoutes", although set correctly and accepted in the URL Path in Service Studio:
the path is still being read in runtime as:
"/directions/v2%3AcomputeRoutes"
by ODC/Outsystems 11. Current workaround works to explicitly decode the URL in the OnBeforeRequest:
However,
since the platform allows special chars in the URL path in a REST Action and doesn't complain or notify, it does not seem right and would make a better UX whilst saving time to another developers like me in future to figure out what's the issue, how to solve and then implement.