Zerotier-one and a reflect server - never even tries to connect

I’m running zerotier-one on a ubiquiti edgerouer 4 at a rural, remote site. I used to use ATT and never had issues. Switched to t-mobile, which blocks UDP, or whatever. Either way, the zerotier-one client cannot connect to the network.

So I setup a pylon server on linode running reflect based on the documenation (running a docker image)
I’ve created a local.conf file in the zerotier-one folder.

When I start zerotier - it shows that forceTcpRelay is true, and the correct IP and Port.

However, it never connects. tcpdump doesn’t show any attemp to contact the relay server.

Are there any steps I’ve missed? Is zerotier-one not compatible?

Interestingly, when I connect to the wifi on this remoet network, and connect to the zerotier network from my workstation, it works flawlessly.