Please see this screenshot. Routine set so that as soon as wifi strength is 1 bar or less (which will naturally occur when I leave the house), mobile data and NFC comes on. Just left the house to go out and nothing has changed. It doesnt clash with any other routines either.
With my bixby routines mines set up so when I leave the home WiFi it alerts me then it connects up to 5g automatically so I can control phone with voice while walking or driving then when I get home it connects back to WiFi, but I did find routines difficult to set up then once I sinked it to home tv and car it went smoothly...Good luck..
I've found that any routine linked to connections based on location work only half the time. My 5G is supposed to turn on when I leave the house, my WiFi to turn off. It never works if my screen is on during the process. Sometimes it works only after half an hour after leaving the house, making it pretty useless and unreliable