Not everything in Tasha's is up on Beyond yet. I suspect the new infusions will be one of the last things to go up, because they need to figure out how to do scaling stat blocks for the errata'd homunculus, and that isn't something their current stat block implementation was designed to do.
I've purchased both Eberron books, Xander's, and Tasha's and the replicate magic item infusion choices are only listing those from Eberron Rising.
Similar problem here and I can't select a homunculus infusion before level 6.
Not everything in Tasha's is up on Beyond yet. I suspect the new infusions will be one of the last things to go up, because they need to figure out how to do scaling stat blocks for the errata'd homunculus, and that isn't something their current stat block implementation was designed to do.
I only recently noticed this myself when theory crafting a ‘flying weapons platform’ 🤣