5 g internet indifferent performance and hanging on by a thread

Please take a look at the following for 5g: RSRQ   -9, RSRP  -99, SINR 2, BAND N41.  I could not locate the ref. chart mention as being in the thread.

A day later I contacted T-mobile second tier technician who advised that my specific address has a reading for 5g of 2.5 out of 10 and I should probably not have the service to begin with. Or perhaps I had simply tried to fix the issue  with too many phone calls and reached the final disconnect.  Phone calls that previous day were garbled, too.

Today is a different story.  Everything seems to work at the previous low quality but it does now work.   This leads me to believe that the big problem has been with the carrier versus my location.  (I mentioned the issues regarding the location prior to signing up.  This was bridged with the "try it out trial period" and I would be even more surprised to find that I needed to try it out for 6 months to know if it would be satisfactory i. e. fair for me). 

And just because I was at the end of my rope, I plugged in my Night Hawk router with cable to the t-mobile device and now the wifi connection is as good as ever. I made no adjustments to anything and it may just be coincidental as I did not attempt to disconnect the t-mobile router in order to avoid conflict with a wifi signal.

So for now Ill ride it out until the 2 years to own the phones runs out or until the moment this distressing loss of service happens again.

Thanks for the help thus far from the community