Could not make a post

I tried to post a message and this forum had blocked me.

Correct the highlighted errors and try again.

• Post flooding detected (user tried to post more than 8 messages within 14,400 seconds)

I tried to post this message one time but there were 'errors' (did not select label). After I corrected the error it accused me of flooding the forum as though the unposted message was in fact posted, as though I was making a dublicate!! I checked - I had not. I tried waiting and doing this repeatedly. Never worked. It just kept tabs of my attempts and said I was trying to make dublicated. Until I changed browser. So infuriating. Come ON Microsoft get your act together. Solving a simple problem is so far taking 2 hours of my time today. What on earth is this...