I discovered this post and updated the gateware.
However, from looking at other posts, the serial number on my LimeSDR XTRX appears to be a very large number. (18446744073709551615 = 0xffffffffffffffff)
It seems like there is something wrong with the shipment, but for now I will continue working on my goal of getting GNU Radio and srsLTE/Open5GS working…
$ ./limeDevice -f
Found 1 device(s) :
0: LimeSDR XTRX, media=PCIe, addr=/dev/limepcie0, serial=ffffffffffffffff
Expansion name : UNSUPPORTED Firmware version : 4
Gateware version : 1
Gateware revision : 19
Gateware target board : LimeSDR XTRX
Hardware version : 2
Protocol version : 1
Serial number : 18446744073709551615
SPI slave devices :
FPGA
LMS7002M
Memory devices :
EEPROM
FPGA/FLASH
FPGA/gold-image
FPGA/user-image
GPS Lock:
GPS - Undefined
Glonass - Undefined
Galileo - Undefined
Beidou - Undefined