the MSR isn’t a secret number, it just the manufacturer specific id, which is in plan speak the model number of the lock. For the FE599 it should be 003B-634B-504C
If you don’t see the MSR or if it’s null or blank that indicates a problem with the mesh communications, some of the commands or responses are being lost in the mesh.
Another thing to check is the raw description and if the mfr, prod or model is null, empty or 0000 that too indicates a communication problem with the mesh and the hub, infact that’s more severe since it indicates that the pairing did not complete properly.
There are many symptoms for this, including programming issues and lack of notifications which are the most common symptoms.
The best way to resolve such issues are to reboot the hub, add a repeater within 20ft of the lock and try to pair the lock again. You may want to see this article which explains how mesh and buffers works and how lack of buffering causes issues with the mesh which leads to issues such as what you’re facing.
Also when pairing the lock, you should reboot the hub first and then pair the lock within 5ft of the hub ideally to avoid signal issues (reflections, inteference etc as pairing is very timing sensitive).