Unable to upload a track

Hostinger Self hosted WordPress version 5.51 website

I use trackserver to upload my cycle tours and have many tracks on my server. I thought one of the tracks became corrupt and I haven’t been able to view it. I keep a copy locally so I thought, as it had previously displayed fine, I would just reupload it. It still won’t show. I then split the track into 4 as it was 85000 points but I cannot upload these. I just get an error message telling me they arent in GPX 1.1 format yet I saved them using Locus Pro in GPX 1.1 format.

If I try to import them to my android phone Trackme I get lots of errors for each point (similar to the example here but by each date point of the GPX) Java Text parse exception error unparseable date “2016-09-08T01:24:34.000Z”

I have no idea what to do to make this file readable by Trackme or Trackserver but it looks like the date format is wrong. I have opened one that works in Notepad and compared it to the one that doesnt and they look identical.

Any suggestions would be most welcome!!

Many thanks Jon