Import GPX into GC App fails

What is the source of these GPX files? Can you describe the process you're using to import into the android mobile app? If you could zip a gpx file and attach it here, we can take a look at it.

GPX’s from various sources and they were consistently imported until June without a problem.
Import of these same GPX’s into GC Web pose no problem, but that is not the solution I prefer.

I'm on Garmin Connect version 4.35.1. I tested with a GPX course that I've used before. From my phone opened the file, then was prompted to choose an app

After I chose Connect, it then opened as a course on the Connect app.

Possibly there is a compatibility problem with the file you're trying to import, which is why I asked if you could zip one of the problematic GPX files and attach it to your thread. Another possibility is that your phone has the wrong app associated with GPX files.

Just as an example a copy of a GPX I used before without encountering any import problem.

The import steps I use are exactly as you described, they result in opening GC App with a pop-up warning: "error loading your course". Existing courses are shown.

test.zip

Unzipped your test.zip then copied it my phone, then opened it, prompted to open with Garmin Connect, selected course type road cycling. It opened as "Cycling Sept 27" I then pressed "done" to save. I made it public so you can see it here.

https://connect.garmin.com/modern/course/43227161

At this point my only suggestion is to uninstall Connect, restart phone, install Connect, restart phone. Then if still an issue and nobody else offers advice, contact Garmin Support.

I'll sleep on it for a while, Maybe after a future update things are restored to normal.