I see...
Looks like SoF+ calls this for start zones if none is set in variables or rules:
https://github.com/EQEmu/Server/blob...rlddb.cpp#L407
And that is probably failing to get any query results for the zone id you set it to in start_zones since that was designed to work for starting zones that are default for the client (not custom).
So, the easiest solution for you would be to just change the safe zone points for Mesa in your zones table. Then, set your startzone back to mesa in the variables table (or set it in rules for the SoFStartZoneID).