When try configure a new wifi say "connection error"
The same wifi work ok, until upgrade to 23.x
You should report this in the beta forum since 23.x is currently a beta release.
I also had some Wifi problems with 23.13/15 as mentioned here: https://forums.garmin.com/beta-program/forerunner-955-series/public-beta-bug-reports/i/public-beta-version-23-xx/can-nolonger-search-for-new-firmware-and-music-sync-not-working
The second time I had problems i could remove the Wifi but could not add it ... simply shuting down the watch and restarting it helped, then i could add my Wifi again. Maybe try restarting your watch?
