TLDR; make sure links you are sharing on Facebook are 'human readable'
What's this mean?
I admin several large Facebook groups and I've noticed the platform is starting to flag non human readable URLs as potential cyber security threats.
As a general rule of thumb, I would recommend not approving URLs that aren't immediately obvious where they point.
E.g., https://evcs30-289aa0bf019a.herokuapp.com/ is a legitimate URL that points to a website where real estate agents in a specific brokerage can download real time real estate data. But...it's not apparent what this website is.
Contrast that with https://smallbusiness.the411forthe719.com/ where it's much more clear what the intent of the site is.
If you want to preserve your platform, use caution in approving the former type URLs right now.