Time zones. Time delays.

I was following a flight, and in flight it jumped from a 4:55 ETA to a 3:45 ETA, which I assume is because it was showing whatever time zone the plane was in (which would be correct considering where it actually was). But it’s supposed to always show my time zone. That is what is shown selected in my profile. What’s the problem?

Also when the plane landed (I was talking to someone at the airport as I was watching FA, then the pilot), FA still showed 30 minutes left, and some miles left, and still airborne on map. Why is it off so much? I thought it was supposed to be 6 minutes or less.

Which aircraft was it?

The aircraft’s flight plan may not have been marked as arrived by the FAA or not closed by the pilot could account for the delay in the tracking.

An hour change in ETA seems like a bit much; usually they’re a minute and rarely more than a few minutes. Can you provide the tail number and flight?

We are delayed 5-6 minutes from realtime, but an ETA off by 30 minutes at the end of the flight is unusual to say the least. Can you provide the tail number and flight?

(KAGC) to (M54), today.
At about 3:35, it was still showing 20 something, 22 I think, minutes left.

The flight plan was closed in the air right after being cleared to land, just as it is most of the time in decent weather at a non-controlled airport.