When I either a) download a TCX/GPX file from an activity, or b) create a route with the new route planner tool, and export it to TCX/GPX, I get a file downloaded to the computer. I copy that file onto the Garmin - in the Garmin / NewFiles folder. I disconnect the Garmin and restart it - no new route on the Garmin.
If I do the same with a TCX file from RidewithGPS, it appears as a route just fine.
I've tried editing the filenames to remove anything that might be problematic (spaces, punctuation etc) and it doesn't make a difference. Don't know if it's a Mac thing, or something to do with Strava's formatting of the XML.
Funnily enough I did just notice that of the 4 gpx files I uploaded (2 at a time) only the latter one of each batch has appeared on the device. To be honest though - I've had that problem on and off for the last 3 years regardless of with site I've used!
I just tried one of the problematic routes again (on it's own) and it worked first time. I didn't do anything funky with the file or name, just dragged and dropped it to New Files. I do have the latest Firmware though..
I assume you are already doing them one at a time?
Funnily enough I did just notice that of the 4 gpx files I uploaded (2 at a time) only the latter one of each batch has appeared on the device. To be honest though - I've had that problem on and off for the last 3 years regardless of with site I've used!
I just tried one of the problematic routes again (on it's own) and it worked first time. I didn't do anything funky with the file or name, just dragged and dropped it to New Files. I do have the latest Firmware though..
I assume you are already doing them one at a time?