Improper Calculation of Monk Martial Arts Die (Arms of Astral Self)

The Monk subclass, Arms of Astral Self, grants the ability to summon your astral arms. When summoned, each creature of your choice that you can see within 10 feet of you must succeed on a Dexterity saving throw or take force damage equal to two rolls of your Martial Arts die.

In the action pane, there is a rollable damage button that is being calculated improperly. It does not seem to scale with the character level and displays the base martial die value. For example: A level 8 monk uses d8s as their martial arts die, therefore summoning the arms should cause 2d8 damage. However the action pain button shows 2d6.

Ah, that definitely makes sense. That particular subclass was part of TCoE.