Wrist is much thinner now only where I wear my Watch series 5

I haven't been able to find too much information about this issue happening to anyone else. I have worn a series 5 since November using the large strap on the smallest hole. About a month ago it started to be too loose so I switched to the smaller band on the centre hole. I wear the watch with a proper fit, just past the tiny wrist bone where people usually wear a watch. A few days ago I noticed that in the area where I wear the watch my wrist has literally become "thinner". There is a fairly substantial indent under the watch face area and that portion of my wrist seems to have lost muscle mass and fat. I have since moved the watch to my opposite wrist. Someone on Reddit suggested that it was like wearing a ring, except with the size of a 44mm watch face it is MUCH more noticeable. This section of my wrist looks like it belongs to a tiny 14 year old girl, not an adult who lifts weights. It also doesn't seem that the muscle and fat has just been moved around, like with what happens when you wear a wedding ring for years. It seems like it has actually just gone away, more like what an arm looks like when someone wears a cast for 3 months and then removes it. I'm wondering if anyone else has a substantial indent where they wear their watch or if this is a freak incident. Other non-smart watches I've worn did not have this affect and I wore them the same way. Again, the band is not too tight. Even if it was, it shouldn't cause such a "thinning" effect anyway.