I think that’s backwards to what I was guessing. But if the fan has some effect, it might be worth trying.
I don’t think it’s blowing the layers out of place but the cooling difference from the fan might have something to do with it.
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Well I bow to those smarter than I. I’m rethinking everything I know about 3D printing, which apparently, was inflated. Hahahah
My dad has a MK3s which had somehow slipped my mind. And since I am on a time crunch I commissioned it for help with these coasters and what do you know… bulges in the same spot. It cannot be mechanical. I did use the same settings across the board. But its definitely the model related to the settings. Which is bananas to me because my dumb brain looks at it and goes “2 circles”, Easy Peasy.
Bambu Lab responded and it was quite thorough, much more than I would have expected honestly. I was impressed. But further more they said almost the exact same thing Ryan did. So in case anyone was wondering, Ryan knows his crap and isn’t a one trick pony. BL even printed my model and sent a pic of it with the same bulge. Crazy on 2 fronts.
They did give me some more specific settings to try which I will give a whirl as I still have like 60 coasters to go. 
Thanks again y’all!
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You can try a full bed, slowing down your print and infill speed considerably. I am not saying you can’t get rid of that bulge, just that it is completely normal for printing fast.
Does the client notice it or just you?
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Tried this with the max I can fit (4). Unfortunately it looks the same as 1 for the most part.
This will be my next test. Got some suggestions on specific speeds from BL so I will give those a whirl.
Makes complete sense and I understand. Just didn’t expect that on what I would have deemed a very simple part. But apparently Im going to school today! 
Your advice and insight has been spot on and very much appreciated.
Honestly I am almost 100% sure he will not notice and since it is the same on all of them, I don’t think he will question it at all. Plus by the time I have them done he will be giving them away like the day after so he’s not going to sit there and study them.
Honestly this whole job has been rushed and I am somewhat regretting taking it because I feel like my standards have been reduced a bit to get it done. But the $$ looked to attractive and got the better of me. In the grand scheme the bulge is quite minor for what it is and what its for. More so at this point Im curious to find an answer for the future job where it might come up.
I have a lot less experience than other here. But my first guess was over extrusion. At that layer, the infill goes to 100%. 100% is usually a problem because you can’t perfectly fill all of the gaps, so any gaps end up pver extruding somewhere. You can try reducing the extrusio. Multiplier or printing the entire thing in 100% infill (as a test). As for the assymetry, maybe the outermost line is firmer on one side than the other, due to the fan. And the softer side is giving more. Or maybe it has to do with the order the layer lines are laid down.
The easier, more permanent solution may be to add some sort of interesting design or assymetry to the outer edge. You can make a cylinder on a lathe. Making it dragon scales or knurled or waves or hexagons would show off the printer more and hide the imperfections. You could do something as simple as having the base flare out below that point, which would make any inconsistency look intentional.
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