You have misunderstood the duplicate post. A glitch either
with my computer or with this website persuaded me that
my post had not gone through, so I sent it again. Within
seconds I found that both - duplicate - posts had been
accepted, so one had to be cancelled.

I didn't find any way to cancel a post so I amended the second.

If I did not want people to respond to my posts, I wouldn't
post in the first place!