Region : Greece

Model : TL-MR3040

Hardware Version : Not Clear

Firmware Version :

ISP : Cosmote

Please excuse me if I'm in the wrong place!
My problem is in finding a wireless router compatible with my newly bought ZTE MF821D 4G modem.
My local supplier offered me 2 models, both TP-link, but the TL-MR3040 (V2) was the only one to offer any compatibility - I found the reference "MF821" (without the "D" suffix) in the Australian list of compatible modems!
My supplier tried for over an hour today to set up my modem with his TL-MR3040, but although it connected initially, the router kept disconnecting and re-booting.This suggests to me that it probably is compatible, and the problem is either with the hardware version or something else minor, but I wonder if anyone can offer any definitive information? Is the specific modem "MF821D" compatible with hardware version 2, or is it only the "MF821"?
I can confirm that my 4G modem works perfectly when plugged straight into the computer, but I need a router to share it to 2 users.
Any help appreciated, as 3G almost lurches to a standstill as tourists hog our bandwidth in August!
Thanks.