I believe that there is a typo in the Summon Construct spell from Tasha’s Cauldron of Everything. The spell is shown as a 4th level spell in the spell listing and in the table at the beginning of the chapter. However, the hit points formula in the Construct Spirit stat block is given as "40 + 15 for each spell level above 3rd," emphasis mine. This is odd because all of the other stat block formulas are formatted such that you only add extra hp if the spell is cast at a higher level.
RAW the construct has 55 HP when cast as a 4th level spell, but have the designers commented that this was unintentional and the base HP should actually be 40?