Darn that stinks. I just got mine setup using the LTE backhaul and i'm getting pretty decent service. Still can't use it to make a call no VOLTE however it is nice to be able to use the LTE for my phones and spare the WIFI for other devices.
After seeing this comment, I tried a couple of things and viola, it works. Unfortunately I still wasn't successful connecting to the network. It was a bit tricky with the pi because it has a hard time initializing the modem after a reboot if I don't cycle the power on the modem too, of course that's resetting the IMEI. Working quickly I was able to get it all synced up, but still kept getting the Call failed/Out of Call errors in the logs. If it would have worked I would have worked harder to figure out a way to pass the AT command prior to bringing up the network. I did verify the IMEI with AT commands and uqmi as well.
I have all the connections I need, but I am unable to find the thicker 1.13mm coax pigtails. LTEfix doesn't seem to have them either
I ordered a ZBT WG3526 since it seems pretty well supported, and based on your comments I am going to get a beefier power supply for it as well.
On a separate note: I figured out a couple of things about the Askey router, not that it matters much those little MHF4 looking connectors on the antenna traces look like test points. When you use the proper cable it acts like a switch and disables the antenna while taking measurements. MHF-SW23
Also there is a serial port nearby the sim slot that is marked Tx, Rx, Gnd on the flip side of the board. I was able to watch the board boot by hooking up an arduino like a jerry-rigged ttl cable, no shell though. I saved the output if anyone cares.
I've come across a number of Crown Castle oDAS nodes (small cells) on T-Mobile. I think a bunch used to belong to MetroPCS. I found 3 in my own neighborhood and one in Williamsburg. The ones on my neighborhood all share the same the same eNB ID which makes it annoying to track on Cellmapper since it's 3 separate "sites" but only one marker.