First time I've seen this thread.
Regarding most of the responses, note that the OP says "I noticed that
before the tyre changes start, there are a few seconds where my pit crew does nothing?"
Refuelling comes after tyre changes.
I don't have an answer.
Pitlane speed is pitlane speed.
I understand/assume that the delay in seeing your car reach the pit-box is inline with your pit position and pitlane travel distance, so everyone is slightly different.
It may be part of this process, just the graphics falling inline with the time required.
It seems unlikely every time this happened there was an impending penalty.
So while it does sound unusual, I'm less inclined to think something sinister is happening.
@nuu1212
No need to run "less than full power".
Short shifting is your friend. 👍