This is pretty normal. Welcome to the adult work.
It is an extremely competitive, cut throat niche.
You can have 1,000 websites if they have no traffic you make no money.
What i'm wondering is why have so many websites, why not concentrate on 1 and built that up?
If you're autoblogging I guess it's fine but if you are manually adding these videos I would work on 1 website instead of spreading it all out.
I get everyone wants to be like pornhub with the pornhub network and have a bunch of porn sites linked together. It sounds great, in theory, but when your a small site sitting there embeding videos it's better to work on 1 site at a time until it gets huge.
Just my 2 cents.
But yet, adult ads pay very little and you need a shit ton of traffic to just make pennies.
Off topic
I really like what you did with your network/domains it's kind of neat actually. I'm looking at
https://redlight.top/ and all of the websites. Pretty cool.