Pretty common here in Texas. The taxi-in is noticeable after a few minutes on the ground. After it’s shut down and heat soaked, it’s even worse.
The AFP fuel bypass valve helps with the restarts and makes the stumble less noticeable. But on seriously hot days, it doesn’t always fix the stumble as there’s just too much heat for the small amount of fuel needed to idle.
Until a high volume of fuel runs through those lines and cools them down, the stumble persists during hot ground ops. Once the rpms come up and the fuel starts flowing in a higher volume, there’s enough thermal mass in the fuel to make the engine operate smoothly.
... then, of course, once you’re flying you’ve got the added cooling of the air on the lines.
What you describe is something we see here pretty frequently in our local -10 fleet.