Facebook Messenger unavailable post

My account is for affiliate linking. Very simple flow... comment trigger word, youll get a greeting message via ManyChat and then you’ll get the actual link via ManyChat. With Facebook messenger, I have the link set up as the second message. The first message (because ManyChat AI bot told me to) is a greeting. For some reason when someone clicks the button for the link, its says “post unavailable”. The strange part is it doesnt happen all the time. Sometimes it works for one person and that same manychat link card doesnt work for another person, they both could be following my account. There is no rhyme or reason for when it happens. I’ve tried all the troubleshooting. Nothing seems to work. It happens with my LTK links, Walmart storefront links etc. Has this happened to anyone else? Is there a crucial step Im missing?