BR1 max: Have to re-enter PIN code every time I want to use SIM B

So what happens is I move into an area where SIM A provider gives low bandwidth, so I like to switch over to SIM B where the provider maybe has 5G signal. But then the router is unable to connect stating it has the wrong PIN code. I re-enter the PIN code, and sure enough, now it connects. Thing is I have done this numerous times. So where does the PIN code go?

Is it possible to use the router software to remove PIN codes? - I don’t really need them for anything.

Just now the same thing happened when switching from B to A. After waiting maybe 2 minutes the error message went away and it started to connect.

Is the 6 asterixes in the pin fields just to cloud the real PIN? Or is the software changing it by itself somehow?