SIM 1 slot not working properly

[Members_yVUjdJt]

Since 2 weeks ago I found something very weird on the SIM1 

In some area connection keeps dropping off, it is on the same network as SIM2

I did a swap, the same, SIM2 seems to be working well but SIM1 is working on and off.

I bought the phone through work so it came from original Samsung in the Netherlands, not sure what to do, changing to flight mode and turn it back on will fix it temporarily, however, in some area it won't pick up signal at all 

Not sure what to do it's very weird. 

[GalaxyA51user]

You are using Netherlands S21 in UK? Network bands may be different. Try to flash with Odin G99xB BTU firmware. x stands for whatever S21 device you have, Base, + or Ultra.

[Wilas]

Got the same issue with a UK model bud after 1st Dec update phone was fine beforehand SAMSTUNG

[arzigogolo]

I have had this problem from the beginning with S21. Every now and then I have to open and close the SIM slot, then for a while it works.
That's why I wanted to switch to eSIM, but you can't have two active eSIMs on this phone. because they only work on SIM2!

regards

Stefano