Travel & Surf Zone 2 (USA only 5GB)

Dear T-Mobile,

I am currently staying in NYC using Travel & Surf Zone 2 (USA only 5GB). I’ve noticed that after any metro ride(in which they do not have internet connection), my local provider changes from T-Mobile to AT&T and even though I still have enough data left, they show me pop ups that my data is not working and that I have to top up my data credit; and the disconnection stays until I connect to any sort of wi-fi for around 5 minutes or so, after which the mobile data works normally.

I won’t be coming back to the Netherlands until mid January, and so far this has been happening on a daily basis, which I surely do not find ideal happening for next 3 and a half months. Are there anything that T-mobile NL can do about it?

Thank you for the support and pardon the English, I deem my Dutch insufficient to discuss such technical problems :)