Both sim cards have stopped, how can I get them working?

[Windows Central Question]

both sim cards have stopped

Good morning to all
I?ve changed my Lumia 630 DS to a Lumia 640 XL DS not lte.
I?ve used a Nanosim card for my 3g/2g flat rate and another one from the same operator to make calls.
I?m under WP 8.1 and all is updated.
For me, both sim cards have stopped. In the cellular menu +sim, I cannot find my sim cards.
Indeed, it?s displayed in grey ?Sim 1 setting? , sim card one, and it?s the same for im 2.
I can?t put my phone in plane mode, and I have then to restart my device. It works fine for a time and? and restarts again.
I?ve changed my internet sim card, but the problem persists. I?ve permuted the Sim cards,,, it?s the same.

 

[roi_noir]

Re: both sim cards have stopped

sorry I forget to add :
" What I must do ? change the device ? the sim cards ? or other thing ?

Thanks "