I have whittled down an issue in Garage UI, of not being able to select "Garage" along with reduced selection area of "Store" and "Player Account" tabs is due to the "Hanger Booster Viewer" by Polyacov_Yury. There is no support page for this Mod. I think it maybe a result of the reserved icon area being too large. By unchecking this mod in your modpack, selection area returns to normal.
KillerTuxmen