When you are creating custom time settings in the Web GUI from the Configure Time Settings screen (Administration → Device → Time Settings), with the local time zone field selected as Custom, the documentation for the name field is misleading
The online help for the name field states "A symbolic name for this time zone, which is appended to local times. It must be three or more characters long and must not contain a leading colon, embedded digits, commas, nor plus and minus signs." However, the name field only supports alphabetic characters.
Diagnosing the problem
If non-alphabetic characters (such as parentheses) are used in the name field, the time will display as UTC regardless of how the user configured the hours from UTC field
Resolving the problem
Only use alphabetic character in the name field of custom time settings.