I tested, and here is working:
First I allow the “add as root” in developer options:
Then, set the type of USB connection, in swipe down android menu, as PTP:
(I think in the past I choose the “transfer files” option, but whatever, adb only recognize it in PTP)
Then, in terminal (PC):
adb devices
adb root
adb remount
add push libjni_latinimegoogle.so /system/lib/ (use the "/"in the end)
adb unroot
adb kill-server
Then, reboot the phone