The "phobia" often comes from experiences overseas, especially in Europe, they feel mistreated by some migrant groups. For example in France, North African gangs commonly target Chinese businesses and common people because some feel, "The Chinese have become too rich in France... I think it's not fair,
they are now in a category of people with nice clothes and big cars" like for some reason Chinese must be cast into a group without nice clothes and big cars because they arrive poor, or another put it, "that's the way it is, I don't like the Chinese, I don't know why but I don't" (1:00 of video), who has an irrational fear or dislike?
Most of Chinese that goes to France arrive with little money, they work hard in order to improve their conditions and not harm other groups in the process. The fruits of hardwork is seen as unfair by some and feel resentful towards the Chinese as a result. Some will rob and assault Chinese because of this resentment. I am not aware of Chinese attacking these other migrants for money or pleasure. They merely pursue a defensive reaction, not attacking others. This begs the question, should society pursue equality of results or allow an open playing field? There is no right answer, just depends on the values of your society.
It is well known in the Chinese American community that African American gangs target Chinese businesses and homes. They even rap about it.
"
First, you find a house and scope it out
Find a Chinese neighborhood
'Cause they don't believe in bank accounts"
As a reaction to this, many Chinese Americans especially newer arrivals from PRC (tend to like guns) started to arm themselves and acquire arms training as a reaction to violence against them.