I don't know the exact problem, but there are many factors.Have you been able to find a pattern for these profiles to achieve more reach than others?
Because I'm also in this search wanting to understand why, my profiles have a very bad reach, but I see people posting in groups and having a lot of engagement but I don't understand why, some profiles have enough reach in the group and other similar profiles don't have .
I really wanted to know why and if there is any pattern to follow.
Yes, that's true.Knowing how Instagram works, i think the first 10 minutes matter the most BUT i am pretty sure every FB account has it's own trust level AND the post is scanned for spam/hate speech etc.