Following Lemmy on Mastodon is a truly terrible idea. If you subscribe to a community here on Mastodon, you will get every post in every thread. Your Masto feed will be an unreadable pile of out-of-context garbage. There’s no over-zealous bot. That is just how it works.
Kbin allows you to use both Lemmy and Mastodon but doesn’t crowbar them into the same feed. That might be your best bet.