monster level

im in a t16 map, with irradiated tablet and +1 monster level in a cleansed area, it was supposed to be a lvl 82 map right? the monster level is 81

I have a T16 map in a corrupted area with powerful map boss and the point in the tree. Map before opening shows monster level 81, inside the map aswell!

I had the absolute same thinbg before. Took pieces out, in again, out and suddenly the 81 was an 82. No idea what I did, but I am pretty sure it is a bug.