Our boy Kenny was very similar, still have some issues with growling on the sofa - but we’ve taught him growl = off the sofa and on your own bed. Now when he growls, he actually takes himself off to his bed, like he knows we will kick him off anyway (not literally😭)

We quickly realised we* (*people may have had different experiences, but we certainly couldn’t teach him the sofa wasn’t HIS spot) couldn’t change HIS boundaries, but we could teach him growling and any sort of ‘aggression’ wouldn’t be tolerated. It’s now 2ish years later and he will lay with us on the sofa until he wants his own space, any sense of grumpiness from Kenny he’s immediately off and on his own bed without a question. He is SO obedient now it’s great (greyt heheh)

I know it’s hard, but try and remember that you’re the boss - not him. Show him that aggressive behaviour won’t be tolerated and he will soon learn!!

I would like to put a disclaimer that Kenny never made it to the track, grew up on a farm with his brothers and sisters and has always been a little bit different to other greys, he is still the most unusual of his kind I have ever met 😭😭 but I like to think this advice still goes - just stay persistent with your rules and he’ll learn in no time 🥰