From the Garmin documentation (https://developer.garmin.com/connect-iq/core-topics/app-settings/) there is no mention that alphaNumeric type does not accept <, >, & and \ characters. These characters are accepted by Garmin Connect Mobile Android so I don't see why wouldn't be they accepted in iOS. For some reason, Garmin Connect Mobile iOS behaves differently when trying to save the mentioned characters:
- When using & character, the character and content after it will be removed upon saving (e.g. "ab&c" will be saved as "ab")
- When using \ character, the character will be removed upon saving (e.g. "ab\c" will be saved as "abc")
- When using < or > character, the whole string is cleared upon saving (e.g. "a<b" will be saved as "") and then you get redirected to an unavailable page:
Related thread from few years ago: https://forums.garmin.com/developer/connect-iq/f/discussion/5459/ios-gcm-ciq-settings-strings-do-not-accept-and-characters, where only characters + and % were fixed.
