Houdini Cyano algae - thoughts

[Cal_stir]

I've used chemiclean and never had any of those issues, I have 2 pod eaters and lots of pods, you have to turn your skimmer off for a few days and use air stones for O2, Dinos are more photosynthetic than cyano, thats why they appear and disappear with the light, if it's dinos the bubbles and strings will appear eventually, cyano mats hold nutrients and the cyano feeds itself and is less reliant on light.
You have dinos IMO, a tougher fight but winnable, it is important to ID exactly what you have.