Yesterday I added my signed message to the Tomatocage's thread for stacking bitcoin addresses, but then I realize that I cannot verify it online, only in my wallet, and deleted my post. No point to post it if it cannot be verified online.
So thankfully found this thread and I know why. Almost no info in Google tho.
Seems that the SegWit addresses cannot be used to sing messages at the moment, even if you have this feature in the wallet.
I guess I have to create a normal address only to verify my account here.