Firstly, I'm sorry for not explaining it decently in the op.
My first problem is that sometimes when I post (I can't figure out how or why) I get the error "your request looks automated; Post discarded" like in OP's pic. Today I tried to make a thread and got that response twice. I do not know what I did to cause this. It's not the first time either. My post didn't contain links or anything. This seems like a different thing from flood (the error message is not "flood detected")
My second problem is with captchas. Sometimes my captcha gets refused even though I am kinda sure that it's correct. I do understand that without proof you'll assume that the problem is between the chair and the monitor though. I'll try to record evidence if I can