Are there no Piccadilly line tubes from London to Heathrow T4 today?

[T4qn]

Is the terminal closed for some reason?

The only trains coming up on the board for the past 20 mins say they are for T2/3 and T4!

When I plug the stations into Google maps it says there are tubes to T4 approx every seven minutes but that’s not what’s coming up on the boards.

The TFL website is currently showing delays on the Piccadilly Line between Acton and Heathrow. That might be why there's no T4 showing at the minute