Different generations of Samsung may behave slightly differently … but it is a regular thing that a Samsung may not fully unlock until Remote Monitoring decides the device is in normal use. In recent generation devices it is recorded that Prenormal is not displayed but is active.
Another move is to check for updates in the Samsung UI, this will trigger a connection to RMM… many other things that might happen listed in Know your hardware - Samsung Troubleshooting section. The possible need for Samsung account on the device to satisfy RMM is also mentioned; but such account must be removed after unlock is indicated and before flashing a custom ROM.