Bullseye markings on Aeridis Flabalata

[Longroots]

This year I moved my Aeridis into my new setup under grow lights and away from my cooler window. Its had these weird markings on it for a while and they're slowly expanding. I can't figure out what they are and have been slowly growing in size over perhaps 4 months? They're not a different texture to the rest of the leaf (which worries me that its a systemic issue). It also hasn't flowered this year, and growth is slow.