Others with this problem on Lineage have found success by flashing updated modem. Don't know if it works for RR; but if RR is a fork of Lineage, then it's worth a try:
...this didn't work, but I kept on searching for different modes etc. (I added spaces to the links, since the forum rules didn't allow me to put url links in my post)
The one that worked for me was here: >> yadi . sk / d / 4deJEi40cpMvv
more different firmware updates: >> 4pda . ru / forum / index.php?showtopic=481697&st=2280#entry28294818
now the SIM is working well, thanks be to God & the developers

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