I've noticed that when an artificer levels to 10 the enhance item infusions do not increase within the item itself. For example, a warhammer with the enhance weapon infusion for a level 10 should have a +2 bonus but is still only getting a +1. Is there something I'm missing to get this to work properly?

You’re not missing something, it’s a glitch. Others have reported the same issue. Here’s a link so you can see your not alone.

https://www.dndbeyond.com/forums/d-d-beyond-general/bugs-support/66273-artificers-infusions-not-scaling-with-level

But don’t crosspost into that one, it might confuse efforts to fix it!