I agree, I have no clue WHY they put the 2019 box on the 2018 1040X....At first I thought maybe it was just an on screen "typo", but I couldnt get the amended figures to flow properly unless I checked the 2019 box and then it printed with 2019 being checked which is no good! so I waited for another update before attempting any 2018 amended returns.

Ugh, that sucks about CO!   What a hassle!