I've tried editing my first post, a random one and I can't ping again a group (in this case buysellcw). I just can make a new ping in a new post, but I see a lot of people who pings the group without doing that.

Please, ping me with your answer. And thanks. <3

You can just edit your post, put a space in the original ping, and then edit it again and remove the space and the ping should go through.

It worked! Thanks so much. <3