This has been around for a long time. I reported it 2 years and 3 months ago.
It happens when you send a ship a long distance, and it meets a new race which causes a conversation box to appear. The info box in the lower-left stops updating. It also happens if any type of conversation box or info box appears while the ship is moving. It also happens when you attack something. The attack move is not counted. I think that's what you did here.
You didn't suffer any damage here, but the damage information in the info box also is not updated. This can cause an unexpected loss of a ship or fleet if you use the damage information in the info box to decide to make another attack. I know from experience. You should never trust what is in the info box if your ship has been doing something.
If you select something else, then select the ship again, the info box will have the correct data.