Select B1 as Primary Band on ZTE MF258 Router with T-Mobile Poland (ZTE_STD_V1.0.0B08)

Hello,

I live in Poland and bought from t-mobile the ZTE MF258 router, I currently have firmware (ZTE_STD_V1.0.0B08) installed.
The issue is when using the band lock function or even the full band option, that I have no way of selecting which band is the primary band.
For instance I would like to have first B1 as my primary and then for aggregation B3 and B20.

But the router always takes B3 or B20 as its primary. Is there any way of forcing B1 to be my primary band?

Thank you in advance for your help.

Has the firmware been updated?

>>20303317 On the well-known Polish auction portal "A" there is a guy who issues a service of firmware update to B11, I bought to B08, but in time it jumped to B11 by itself after his service. I've asked him a million questions (including how to configure the router for one particular tower) and he always explains everything clearly. pzdr.