Guys, seriously.
So many noobs in here lately.

1. v8 is not v7. It's a new algo version, it hashes a bit slower and draws more power. It's the same for everyone. Deal with it.
2. Monero difficulty adjust slowly over several blocks. If hashrate drops suddenly it will not become profitable immediately. Read up.
3. More power draw = more heat being produced. At the same cooling level it means your cards will run hotter. Increase cooling or deal with extra heat.

If the devs had not forked the algo, your Vega (that you didn't spend time testing with) would have become useless to mine XMR with within the scope of a few weeks.
Dimwit.