You're not losing it. Shadow figures interacting with you directly is actually way more documented than people realise, most accounts describe them as passive observers but deliberate gestures get reported more than you'd think.
The waving thing is interesting though. Was it a slow wave or more like an acknowledgement, like a nod kind of movement? That detail matters imo because some researchers reckon the more "aware" ones are a different category entirely compared to your typical residual shadow.
I do EVP work mostly but I've had one experience in my own hallway, stood at the end of the landing just watching me. Never moved, never acknowledged me at all. Yours sounds like a step up from that and honestly I'd be setting up a camera if I were you.
Anyone else had one actually react to them? Curious if theres a pattern here.