This is what is supposed to take it out of SOS only mode :
QUICKLY press VOLUME UP -followed by
QUICKLY press VOLUME DOWN - followed by
HOLD down side (POWER BUTTON) until APPLE icon appears...DO NOT LET GO WHEN POWER OFF SLIDE APPEARS,keep holding,it takes about 30 seconds or more on my iPhone 11, DON'T SLIDE THE POWER BUTTON ICON! JUST HOLD AND BE PATIENT....I've had to do this several times the second time it happened but this is the recommended "fix" from online forums. We shouldn't have to deal with this,so although this helps,it's not a longterm fix....that comes from us speaking up and complaining until a permanent fix is produced by APPLE. Hope th his helps you.