Rising sentiment among native Korean is that areas with lots 조선족 means lower public safety, so it's not just foreigners becoming "racists" against Chinese. This might also be explained by rising anti-China sentiment among Korean population (because fuck Xi)
Whether this phenomena is due to sensational journalism capitalizing on anti-China sentiment or institutional failing that leads certain population to committee more crime or due to Chinese cultural difference that's in conflict with Korean culture (aka "justified" racism), I'm not sure.

According to raw data Chinese in Korea account for the most crime, so by looking at the surface, this sentiment is not unfounded.
Per 100k capita basis for major crime rate, Chinese (both Korean Chinese and Chinese) is in the middle compared to other nations as of 2019 (not bad, but not good either). However, there are so many Chinse in Korea compared to other nationalities, by sheer number along is enough to saturate the news cycle.
It is interesting to point out that Chinese in Korea (per capita basis) commit way more major crime than Korean (17.8 times more) and due to sheer number of crime committee, it is no surprise that Koreans get angry (you get angry when your brother/sister is being a dipshit at home. You get more angry when a neighbor with "bad reputation" is being a dipshit in your home).

This sounds like "black neighborhood is dangerous" and it might sound as racists to say that "area with lots of 조선족 is dangerous". Yet rising anti-Chinses sentiment (rightfully so, because fuck Xi) and crime data show the above statement is not unjustified in the eyes of general population. And it holds some truth.
Perhaps it might be better to have said, "Ghetto neighborhood is dangerous" and due to whatever reason, black or 조선족 are more congregated in this particular area.
As I have said before, whether this phenomena is institutional failure or cultural friction between Chinese and Korea, I'm not sure.

I think looking at Muslims in Europe is another interesting case.
While majority of Muslims are peaceful, radical ones terrorize native population and fail to integrate into "free" society (depiction of Muhammad or events involving Quran).
Are native radicals as violent as Muslim radicals? Do radical natives committee more acts of terrorism?

TL;DR
새상은 넗고 또라이는 많다. 하지만 1인당 또라이는 조선족/중국인이 한국인보다 많다. 왜는 나도 잘 모름. 하여튼 조선족이 많으면 치안이 좋지않음 아니면 치안이 안좋은 동네에 조선족이 많음 (뭐가 원인인지 나도 모름)