You’re trying to apply a bevel over a polygon that has an extremely sharp angle AND is too narrow for the bevel anyway. The algorithm is not smart enough to taper the bevel that way.
For the side visible in your screenshots, you can get a somewhat better result by excluding the first two edges of the rounding next to the sharp corner (the beginning of the concave edge). This forces the beveler to taper the armrest edge and to stop the bevel of the crease before reaching the sharp corner.
However, this doesn’t help with the other side that is not visible in the screenshot. Here, you have a fan of polygons and a complex pole located in the area to round. This will not work (not even if you connect the polys as ngon, which sometimes helps).
You need to get rid of the sharp corner and the complex pole in your low-poly base model to give the bevel deformer a proper base to work with, or alternatively you could model the edge cuts manually and use an SDS on it (bevel deformer in solid mode will show you how to do that for the “working” parts, exclude the edges of the not working ones, then make editable and add the needed cuts).
(EDIT: mrmoose’s solution apparently not only gets rid of the fan but also makes the sharp angle work with the bevel algorithm, which seems to be smarter than I want to give it credit for It actually removes the incriminating poly before it gets “dangerous”. However, this solution still creates artifacts as the topology of the beveled mesh contains sharp angled polys again. I would still recommend removing the sharp angled polys.)