I have the same problem. I would like to create a variation of a course I already created, just two weeks ago, but suddenly I get the same error. I'm in South Africa.
It's working in my area. However, if in your area you're getting the error "limited popularity data," you should report this to Garmin Support via chat or phone - https://support.garmin.com
It might have been a glitch in the system. Trying to replicate the error so I can post the screenshot, everything worked again. I have been experiencing issues with the app yesterday as well.
