Question Why do nicer microphones not work with VOIP softphone connected to an autodialer?

Oct 8, 2021
I work for a remote call center. We use a VOIP softphone to connect with our autodialer. I have a RODE NT-USB microphone and a separate headset. They do not echo at all in any other voice program (Discord etc.), but callees say I sound echo-y or tinny. The IT guy said it might be because there are multiple microphones (maybe he meant diaphragm capsules?) in the higher-end microphones

Any explanations or guesses are welcome. Otherwise, I have to wear an incredibly uncomfortable low-end USB integrated headset for 10 hours a day. This is also absolutely killing me with curiosity. I have spent a considerable amount of time thinking about this and I cannot think of any reason it should not work. Maybe it's overloading the telephone bandwidth? But then it would be static'y not echo'y. The bottom of this mystery beckons me every day. I must find the end.
Your work IT people don't have any options for you? Or all the other people you work with? They don't have this same issue? Are you using any sound processing like noise-canceling?

Really the fix would be coming from your company tech support people since they control the setup.