Long time lurker here, but wanted to report the same issue.
I have a Mark 2 Trophy LR and I'm based in the UK.
I took it for it's service last Monday and got the software updated to r59 during the process.
The hotspot functioned perfectly on the way there but hasn't worked since.
The app still works, but the car now frequently shows 2G in areas it used to show 4G.
Regardless of if 2G/4G shows on screen, any connection to the hotspot shows no internet. The toggle in the data management tab can be turned on, but turns straight off.