Weird raised black legiones on Rhynchostylis roots
 

I've seen these black dots slowly spreading across my Rhynchostylis roots recently and I've never seen anything like them. Hydrogen Peroxide 6% seemed to do very little.
Any ideas on what this is?

I don't know what those are. Do the roots dry between watering? What are your temperatures and humidity?

6% is too concentrated to use on living things. That can definitely cause root damage.

Those spots remind me of insect eggs and fungus.

It's semi hydroponics, there's not really any root rot though... Also this is 2 days after the application, so no visible damage.