Hey there!
I have troubles with segwit transactions on mainnet. There are two types of them - native segwit program and nested to p2sh. It is easy to send 2nd type transaction and it is mined almost instantly. However, native segwit transactions like this: Litecoin Transaction are mined by single pool only (1% hashrate), thus tx gets in block once in 5 hours.
Does anyone know why is that?