having inconsistent internet issues

Unfortunately, yes, that’s normal.  T-Mobile’s home internets service is not for the user who needs decent consistent performance, ie, gamers, online realtime classrooms, work from home users, etc.  Your performance is actually better than mine - my download speed frequently drops to 2 - 3 mbs and everything starts buffering, and my upload speed is similar to yours.

I’ve got 18 months of frustrating history with T-Mobile at this point and the only things they’re good at is lying about how they’re going to fix my problems and then whining about how sorry they are when they fail miserably to do anything useful. 

I’ve swapped out their gateway multiple times with zero improvement.  Currently waiting on another gateway swap, this time supposedly to a newer model.  Also currently waiting on yet another tower upgrade that is “...guaranteed to correct your problems...”.  Supposedly they’ve upgraded three towers in my area, each of which was ...guaranteed to correct your problems...”.  Not optimistic about the tower upgrade - hoping the gateway might help.

I’ve got a little more time on the discounted rate they gave me because of all the trouble I’ve had, but if the new gateway doesn’t fix things, I’m going to try Verizon’s new wireless internet service.  If that doesn’t work out, I’m headed back to Cox.  They were (at least for me) on the expensive side, but rock-solid reliable and fast.