Wrangled critter floats in mid-air

Ground-walking critters can occasionally sink into solid tiles after being wrangled, but what makes this more absurd is that if the tile it sinks into is dug out, with only empty space below it, the critter will hover in mid-air in a wrangled state for as long as it remains wrangled, unable to be retrieved by dupes, since dupes need to be able to physically reach a critter's tile to retrieve it. (even though current animation depicts them using the multi-tool from a distance, rather than physically walking over to the tile to pick up the critter)

When the wrangled state expires after one cycle, the floating critter falls naturally to the next solid surface below it and can be wrangled again as normal. Note the passage of time in the clock between the previous and the following screenshot, the two are not immediately consecutive.

It's not obvious to me what condition causes critters to sink into solid tiles when wrangled, but this is the first time I observed wrangled critters floating in mid-air and not falling normally. (Update 737790)