GL-X3000 Spitz AX, just unboxed and put latest firmware on. Compared to my old LTE Spitzv2 I notice that IPv6 from LTE/5G is not being acquired at all. I enabled IPv6 and set to native, same as it works on the older Spitzv2.
The SIM card / data plan are 5g and definitely send dual stack CGNAT and IPv6.
Edited- figured out my FW issues.
But FWIW, I’m getting IPv6 on both AT&T and T-Mobile using FW 4.3.0 Beta (2023-04-15 00:13:08). I’m using “NAT6” mode (as IIRC, I had issues with “Native” mode before when using a hotspot (in Passthru IP mode) on my AXT1800).
I was on 4.3.0 snapshot from April 25. Now on the April 26 snapshot
Date Compiled: 2023-04-26 13:08:11 (UTC-05:00)
I have the “old” LTE Spitzv2 with same APN and same SIM card in the same location in IPv6 Native mode working. With the X3000 it does not acquire IPv6. I will try NAT6 mode but using ULA is lame and outdated, the IPv6 snob in me refuses to ULA needlessly 
I’m with you- but unfortunately, that’s the only way for me to get routing on T-Mo.
… that being said, I haven’t actually tried Native mode IPv6 yet (kind of rushed this morning troubleshooting the issues I’d had), and will give it a shot this evening.