See screenshot attached, with red arrows pointing at the cats tail and shoulder.
Am using 2020 Student Version.
Edit: added SLDPRT attachment of sketch. Maybe someone would like to offer a way to repair it, so that all lines are the same thickness.
It would be nice if someone would write a blog post about that. Oh wait, Jim Wilkinson did!!
See Why are some sketch entities shown in a thick font and others in a thin font?.
Edit: It's late in the evening, and I've had a few beers. I tend to be more of a smartass when I've had a few beers. No offense is intended toward anyone. If I was intending to offend someone I would be much more obvious about it.