Known issue. There are some subtle problems here. Ive wanted to kick around ideas for a potential BIP, but its been fairly low on my list.
My doubt, regarding signing in segwit address is if this is a "bug" and will soon be corrected, or is it an abandoned feature?
If the later is the case, i will probably move back to legacy addresses... I fear to lose airdrops, which may be quite significant.
I think there will eventually be a standard way to sign and verify messages with segwit addresses. But currently, almost nobody will be able to (easily) verify a segwit address signed message.
My doubt, regarding signing in segwit address is if this is a "bug" and will soon be corrected, or is it an abandoned feature?
It is neither a bug nor an abandoned feature. It is just that we are still working on creating a more generalized signing scheme that lets people sign with things like P2SH addresses (e.g. sign with a multisig address).
A signing standard that allows signed messages from multisig addresses would be incredible, I hope progress is made on this eventually.