I have performed the steps to add RSSI column to map display.
The RSSI column is there but is blank.
No values. White background.
The column does sort when clicked as I can see the other columns adjust.

Have used Firefox, Chrome, and Safari with same results.

Any help would be appreciated.

My setup is a FA antenna, FA filter, FA Pro Plus Dongle to a Pi3B+.
Feeding FR24, FA, and PF with no problems feeding.