Instinct 2X: GPX not loaded, too much points

I tried to upload a gpx file with 31km of route, the file size is about 1Mb. There are no waypoints, no turn by turn, just the route.
This "outdoor" watch tells me that it is too big and does not appear in the list of routes. I tried to load it on a Fenix 7 and in 4 seconds I had it available. So I'm returning the "outdoor" watch.

Very slow and old processor, a 1h training run takes 20-30 seconds to save. When I run a marathon it's going to take longer to save than it will take me to run it...

Shameful.