maybe you have set up too many filters, you can check with support as well and they will take a look
yeah, fb is a lot harder to do lately, you'll have to be smarter if you want to keep posting to it and hide what you're doing, this article might help : https://jarvee.com/post-facebook-groups-without-getting-penalized/
good, support always helps
proxies can be at fault, yes. to get out of the loop try these steps: https://www.blackhatworld.com/seo/jarvee-social-media-automation-tool-for-facebook-twitter-pinterest-linkedin-tumblr-and-google.969615/page-11#post-10657192

you around half a year too late, you can get the 5 days free trial though and see how that goes for you