Facebook posting is 100% all about links and nothing else. Facebook is SOOOOOO picky with links, if it even sniffs/suspects CPA or a spam link it will instantly lock your account. I’ve never even encountered issues with proxies/etc, it’s always always LINK issues. I’ve had aged, real solid accounts with tons of followers, groups etc get killed from ONE post with a link I forgot to cloak.
Secondly, you can’t just go posting links on groups, you need to warm up. Make your profile pic UNIQUE, make sure it passes google image check “no other images out there” , setup profile perfectly, post some random statuses, DONT ADD FRIENDS, I dont care what anyone says, dont add anyone, get people to add you. All of my accounts have thousands of friends and I never added 1 person. Hell I wouldn’t even join a group for a day or two. Usually I join some random chat group, post a comment or something, wait till I get some friends, setup facebook actions to like/poke etc. Even then I only join 1/2 groups I want, I make sure I get into them, post something that gets views/likes/comments. You have to look like a real user not a bot.