Home internet and wi-fi extender

From looking at the D-Link 1610 extender information it appears to ONLY support WPA/WPA2 so the best course of action with any WIFI password is to make it longer and more complex if you have concerns about someone taking the time to try to crack the security of the SSID. Given the D-Link 1610 extender is 802.11ac capable it "should" be able to connect to the T-Mobile 802.11ax gateway. There is no yes/no answer that you want. Having worked as a network escalation engineer for enterprise networks interconnecting different vendor equipment one to another in complicated environments I know all vendors do NOT follow the IEEE recommendations and standards 100%. The IEEE standards are intended to allow for backward compatibility of technology but sometimes this is a challenge.

The D-Link 1610 extender can be a revision 1.0 or a 1.01 from 2017 or 2019 so the revision of the extender may also be a factor that has to be considered. If the extender has not been reset to factory defaults before trying to connect it to the T-Mobile GW use the recessed switch on the bottom of the extender according to D-Link's process and start from the beginning. It might be there there is a firmware update for the extender that can help improve the success of the endeavor. Making different vendor products communicate sometimes takes extra effort and time. Best of luck getting that to work.