The infusion says the humunculus' force strike uses your spell attack modifier to hit but the stat block is showing +4 to hit instead of the +6 i get from int + proficiency bonus.

Might of the master is also still worded as it was in unearthed arcana when it was a subclass feature and is therefore unclear about how it is actually supposed to adjust stats.

I also ran into an issue where the thing's max hp was incorrectly set to one. Deleting it and re-adding the infusion/infused item seemed to fix that issue. 

Tl:dr someone needs to check to make sure the d&d beyond character sheets handle the artificer's humunculus' stats correctly and "might of the master" needs to be reworded so it is actually clear what stats the thing should have regardless of when you get the infusion or make a humunculus with it.

As per the very first post in the thread specifically for Tasha’s Cauldron:

 Scaling Statblocks

Several of the new features and spells present Monster Statblocks which scale with your character. This includes spells that summon other creatures. The system to handle these creatures is still under development but we have included inline stat blocks wherever possible to help you reference the stats you need.