My Sim Not Detected in TP Link Archer MR600

It was working fine with one sim, and I needed a new provider, so changed the sim, easy did not get stuck, new sim was not detected (yes inserted correctly)
Replaced with the old sim, which was now also not detected (worked up untill the change.
Bot sims work in another 4G router I have.
 

The SIM card is inserted correctly and firmly in the SIM card slot. It is in a Micro SIM adapter
I restarted Restart the 4G LTE Router with the SIM card still inserted in it. After the device restarted, I checked the SIM card status again on the Advanced->Status page. Still not detected
I Tested the SIM card on another device to see if the SIM card itself is functioning properly, it is workingfine in another 4G router.
I tried all of the above with both the new card, and the card that has been working in the router untill today.

I Performed a factory reset:

Nothing worked. It seems the sim-slot is not sensing the card. I googled and many seem to have this issue, with this router.

What to do now?