tide data is way off

Hi - what am I doing wrong with the Garmin Tide app? I've used the following steps:

1. calibrate alititude

2. mark/save location using GPS on the watch

3. open Tide app (sometimes it engages GPS too, sometimes not, always the same "result"):

Low and high tides are off by hours AND minutes, so it's not a time zone thing either, they are completely different from one another.

Data is off from tide data that every website shows: