When I approached the elevator, an odd round shadow appeared when I walked near the elevator, it only showed on the elevator. It hanged around the top-right area as you can see in this screenshot.
I had a Size 3 Dark Matter mineral chunk, if that might be relevant. It didn't happen on the next floor's start area elevator. (I didn't get to the end of the level after that.)
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A minor thing you also see in the screenshot is that the accessory isn't showing on the top-left area, but only on my playermodel. Heavy Vented Visor.
Is it your sprite's shadow? I count only 3 shadows outside of the elevator circle for two players and two pets. Probably just another bug related to sprites floating.