Using Tread and bluetooth to transfer files from my iPad to the Garmin is not reliable.
There are a number of issue with the Tread App and syncing. I removed it from my setup entirely long ago, but others do use it.

You might want to check out Trip Manager
https://zumouserforums.co.uk/viewtopic ...

CollingsBob

Thanks for the gpx file you PMd. I contains both a route and a matching track.
I first imported to Basecamp and all looked good there.

Next I copied your original file to the Garmin/GPX folder on the sd card in my XT2 and then rebooted the XT2.
I think the XT3 is similar, but might ...

and I have saved them in the correct format

Which format did you use gpx 1.1 or 1.2?
Did you save as a route, as a track, or both?

If you could share one of your files, I'll take a look at it and try to import it to my XT2.
You can either post here or send me a PM.

CollingsBob

I might suggest trying to narrow down where the problem is occurring - e.g gpx file or the Tread App or the XT3.

Maybe start with just one gpx file and get that working.

Does that one look OK if you bring it into something like Basecamp?
Does it contain a track, a route, waypoints ...

It struck me that maybe the manager and the programmers did not have the same definitions for route points, via points, shaping points, ghost points and waypoints.

Based on my own experience, I suspect this is true regarding a multitude of terms, features and expected behaviors.

I use CEP to start almost every route, with good success, no matter where I am relative to the route start.

Things that I am sure contribute to success include:
Checking every planned route at a close zoom level to make sure all via and shaping points are on the road and are not at intersections ...

Welcome to the forum STJ . I have not had this issue myself, but you can find a few posts on that subject here. Some are related to the power supply which seems to be not your case. Yours could be battery related or a hardware issue.

Does your XT restart and work fine for a while or keep restarting ...

I have seen that happen when BC "thinks" a point can not be passed - a closed gate for example or a seasonal closure, etc.
Sometimes real and sometimes not. Such things are really map info rather than BC. Unfortunately, I have never found a way to get BC to tell me what it thinks the restriction is ...

I think it is either both zoom and center, or neither.
BC_CenterMap.png

I typically check "Center Map" then step through the route points one at a time to be sure my route points are on the desired roads.
I also uncheck it and zoom out to see my entire route, then step through the route points to ...

I have, rarely, seen BC do strange things like what your motorcycle route shows, but I have no idea why it happens. I never tried switching to car but I'll try it next time I see the strange behavior, if I remember.