Basically the combo of
1: if you doubt any dogma, even if you’re trying to believe it, you’re out
There's various levels of doubt. Ladislaus was responding to you as if you're guilty of voluntary doubt, because what you said, wasn't clear. And also, since you've left Catholicism for Orthodoxy, the presumption is that you have major doubts on doctrine. Your situation is unclear.
Involuntary doubt (not sinful) -- Hesitation, difficulty understanding Church teachings, or anxiety and struggle to overcome objections.
Cultivating doubt (sinful) -- If you let involuntary doubt fester and intentionally refuse to look for answers or pray about it, you cross into "failing to protect your faith," which can also become sinful. To prevent doubt from leading you away from God, the best approach is to be proactive.
Voluntary doubt (grave sin) -- The deliberate choice to disregard, refuse, or dismiss what God has revealed and the Church teaches. It is a willful refusal to assent to the truth.
Might I ask, why did you switch to Orthodoxy? Was it for the liturgy and a less/chaotic situation (i.e. no V2 vs Tradition)? Or did you switch because you don't like a particular catholic doctrine?