I could make the map renders fine on both sites with just a couple "allow" rules:
https://imgur.com/a/TYQnOFZ

As stated on the front page of the project:

> [uMatrix] is for advanced users who can figure how to un-break sites, because essentially uMatrix is a firewall which works in relaxed block-all/allow-exceptionally mode out of the box: it is not unexpected that sites will break.
> [...]
> Using uMatrix logger is key to un-break sites: the logger will show you all that uMatrix does internally.