The mast I use seems to keep it going as usual. I think I only seen them turn off B1 once... maybe they only do it on quieter masts. I'd imagine the mast I connect to serves a lot of people giving where it is. The only other thing I noticed before was it being around -104 NR RSRP on N78 instead of say -101 / -102 . B1 is operating all the times I've checked so far (and right now using B3,B1,N78).
The weird thing I noticed now with this router is when I was testing if 5G was working ... the previous strategy of powering off for 15 minutes and re wiring inside wasn't working because now it'll always boot up in LTE-A now no matter what.For some reason the behaviour it usually does decided to change and... I didn't know that so I wasted alot of time re wiring and powering off.
I then discovered now that it will go into 5G on it's own after a while of usage. 2-3 mins usually and I just need to keep an eye on it so that when it does connect I can then just start a ping in cmd and it'll hold all day. Waiting on that routerboard so I can use that 24/7/. Anywhere from 300-370 Mbps and about 20 upload. The perfect device would probably be a mikrotik style dish with a mediatek modem. Then I could potentially run B3,B1,N3,N78. Still a mystery as to why N3 doesn't work and N78 does?
The issue with the connection dropping if I heavily download has stabilised alot more it only happened me once yesterday whereas there when I complained about it , it was doing it every time I tried downloading anything over 30mb.
Maybe it was indeed weather related like you said?