Female colleagues who used to like to chat with me after work and eat with me now don't talk to me for half a year. When I mentioned her name, she didn't make a sound and didn't want to talk to her.

There are many reasons for this. You have provided too little information. There are two reasons to bear the brunt. 1 means that someone already has a boyfriend. This female colleague is very cautious about love. How old are you? You work in the same place again? If she agrees with your pursuit, she will stand out in the unit. If you two have problems, it will be ugly at work and will be gossiped. In a word, she thinks more than you, and you seem to be simple in her eyes. That's why you always feel that she is very open and you seem to be around. Obviously, she is more mature than you. I'll give you a hint: if it proves that someone has a boyfriend, you stay out of it. If it's the second case mentioned above, measure it yourself first and see if you can be responsible for her. Adult love is not like a student, so it involves more things. Think for yourself.