Print Bulging at the Bottom of Slots  

Print Bulging at the Bottom of Slots

I'm not entirely sure how to describe this issue as it is similar to the problems of a layers shift or a bowing effect, but it is definitely different from those. On the plus side there appears to be a clear cause behind what is happening, I just don't know why it's happening and how to fix it.

I printed a massive riser stand designed to hold amiibo figures. It is a staircase design with round, recessed slots for the figures to stand in at each level. At each of these levels the print juts out at the same layer that is the bottom of the recessed slots. It is most pronounced on the sides but you can see it on the front, too. Adding to my confusion is that the effect lessens at each step. On the first/lowest step the bulging is most pronounced. By the the fourth/top step you can see a feint line that lines up with the bottom of the slot but there is no bulge. Originally I thought this had something to do with the model, possibly because of how large it is. It was something I would look into later as this was the first and only time this had happened to any prints.

Today I printed a case for holding D&D dice. Once again all along the print at the same layer as the bottom of the slots for the dice the print protrudes out. Looks a little different than the riser, but it's sticking out in the same predictable spot. Once I saw this I knew it wasn't just something with the first model and that it has something to do with printing objects that have a hollow space with a bottom in the middle of the model. It's a obviously a huge blemish to the prints. I have no idea what is could be causing this and looking back this is the first time I've printed models with slots like this. I have had no trouble with my MK3 in the past.

Any help would be appreciated, especially since I don't even know what to call this problem to research it further. Cheers!