could go either way at this point. I know beskar is supposed to be crazy strong, and one of it's benefits is that it really is damn near impossible to hurt with a blaster/lightsaber.
But can it be dented? Damaged? Bent? Yes. It can be mined and shaped, that means it can be destroyed or damaged.
Is the show depicting the beskar getting bent and damaged? We don't know. nothing official have come out and said how it will work on screen, and Disney isn't holding itself beholden to fluff and such that was put out in a novel from the late 90's where this would have been covered. Some of the fun is that we don't know what part of his suits were what at this point, and may not find out for a long while.
The guy at the start of the first episode was definitely implying that he could tell if the chest plate was beskar by scraping it. Do we see the chest plate get scraped? Yes-ish? the blade damages the paint for sure, but paint is paint. I don't remember anything that makes the metal underneath look damaged or not damaged.
Even if we knew for sure that the plate wasn't damaged at all by the knife, and was thus beskar, we wouldn't know what the new cinematic "breaking point" of the McGuffin metal is going to be. The idea of a metal being "boot knife proof", but also being capable of being dented by blasters and cracked in half by giant hairy rhino critters is perfectly fine to me.
I had assumed, originally, that a lot of his gear is not beskar. But I can't tell any more/suspect we're meant to assume it is all/mostly beskar.
Hell, maybe they even make alloys. cutting beskar with durasteel to make better armor than straight durasteel, but nothing compared to the full on mythosaur riders of old. we shall see.
side thought: the pile of beskar gear the armorer has made and is melting down: does any of it look dented/damaged? If it does, we can assume that beskar shows it's damage until its repaired/refinished (or maybe it's all made of the "alloys" I conjecture, and she's just separating the beskar out).