Hello! I have a such problem. The thing is I need to use one Chinese site but when I try to log in the system changes my password automatically! I mean my password, for example, 123456789 and the system makes it "P:KJHGHVcfbvnm,nbhg. I can log in on other browser and on cell phone browser, but it`s very troublesome and almost impossible on Mozilla. What should I do? Help me, please! I need exactly Mozilla. I`ve already tried to delete my password from the list of passwords kept by browser. It couldn`t help me.

You can edit the password field in Lockwise (about:logins). You likely need to create a login block exception to prevent Firefox from prompting you to update the stored password in the Password Manager.