The ingredients must match
The key, algorithm, code length, and time settings must agree. Changing a setting in your generator does not change it on the service.
The timer is a guide
A common setup uses a 30-second step. The service decides which time windows to accept and whether a submitted code has already been used.
Why time matters
A device with an incorrect clock can calculate a code for the wrong window. Changing its displayed time zone alone should not change the underlying Unix time used by a correct implementation.
A practical check
Use a test key to compare tools, or check your account’s setup instructions. Never post a live setup key or full QR image when asking for help.