Go into settingsSettings, SIM and network, and selecting SIM 1 or SIM 2 according to the slot used by the problematic simSIM.
This shows another page for mobile data or "roaming". Roaming is for Shuresure switched ofoff, Wichwhich is the problem here. Turn roaming on. Now, thethe phone will remain silent and quiet.
Bravo ! Please don't forget to upvote and mark as solved.