It was most likely the March security update.
If you have already installed it. Go to Settings -> Software update -> Last update and look at "What's new" for a description.
If bought and used on the same network, you may have to visit customer service. You can try clearing the cache partition by pressing and holding Volume Up and side key (Bixby or power button) until you see Samsung Note10.... Release power while continuing to hold the Volume Up. Once Recovery screen appears, use volume keys to move to "Wipe Cache Partition" and press side/power key to select and wipe it
If SIM in the phone isn't from the carrier you got it from, find a SIM from the carrier, install it and check for update after restart. 3rd option is to flash it if you can do it safely. backup data/phone first though.