Kerbal Space Program

On Xbox, I cannot purchase new parts in R&D.

I used science to research Engineering 101, and on hard difficulty, I also need to purchase these new parts.

For example, the 2HOT Thermometer says "Purchase (Entry Cost: 2,500.00)". I have plenty of funds, yet there seems to be no button I can press to actually purchase the new part. Only X and B do anything, more info and return to tree.

I tried to use the part at the VAB and again, there seems to be no way for me to select "Purchase". Instead it states in the description "Part model requires an Entry Purchase in R&D."