it looks like the map container "thinks" it's only a few pixels wide when the page is loaded.
This may be because it is hidden at first and only gets visible when you click on "maps".
Things you could try:
- put the map on the "Technical Description" tab so it's visible from the start
- in the Plugin options under "GPX track settings" change the Width from 100% to - say- 900px
just to see if that makes any difference.
I have installed the plugin in a website
The problem is that the map is showing but only one part of it until I resize the browser window then it loads completely androstrailrace.gr/en/races/10-km-race
click where it says maps to see it