

I think the issue is you are posting too early for Reddit, you should be commenting for the first week at least.
Essentially, the coarse-grained spam-filter assumes that anyone that has a whole bunch of posts ready to go the day they sign up is a bot spammer. Even here on Lemmy, if you sign up then immediately try to copy and paste a post 10 times to different communities, you will get reported and banned for spamming.
The principle behind it is like any social space online or offline: if you are a legitimate new member, you will start on the fringes and slowly settle in, from introducing yourself to a few members, attend events, to then asking questions, before making any influential speeches or going into a leadership position. Anyone trying to fast track that will be met with suspicion from members.
Reddit and Lemmy are similar in a sense. you start as a lurker, become a commentor, then you are well-adjusted enough to post.
Well, here’s hoping you have a better time with us on Lemmy! My Reddit account is 8 years old, but I stopped using it and have been on Lemmy full time for 2 years now.