Actually there are two cases for this hygrometer (amazon link here), made with Onshape, in the 3mf file. I made one simply flat and another with a 15 degree angle (see photo).
Deeply sorry to read that.. :( I did more than 5 prints here, different layer heights, all went smooth. Forgive me to ask, but did you level your printer? I always level mine when I change plates.
Came out perfect, printed in the sample green PLA spool delivered with the printer. Since I had some spare round hygrometers for use in dessicant boxes inside the AMS, I printed this to put them around the house.