+1 to the OP. Good catch. I'm surprised I didn't catch it. I've been scrutinizing the rule system all over the place.
And you're right. When enemies are invisible, it sucks.
Interestingly, they made phase spiders mad teleporting across huge distances spitters, and their implementation of invisiblity would have been perfect for phase spiders instead. They phase. Can't hit them or detect them and they can move about however they want until they phase back.
So, Larian, adapt phase spiders to use this homebrew version of invisiblity, and make invisiblity per actual 5e rules. Then, we're good.
