Phrag. With light burn or something else?

[lerera]

hi everyone,

I have this phrag. Ingrid Portilla
For 7 months now. Shortly after getting it, it started to have the top of his leaves covered with this brown lesions. At first I used to sterilely cut them out, making sure I have a distance from the affected area but it keeps on coming back. Recently some other phrags, Mostly seedlings, started to have similar changes but not to the same degree.

My orchids are growing indoor under light but very intense light (2 x 80w colorful lamps, 2 x Yescom 225 White LEDs Grow Light Ultrathin Panel and 4 x fluorescent grow lights) all in distance if no more than 2-3 ft from the plants.

Does anyone experienced these changed from just light or is this secondary to bacterial/fungal/viral infection?

I Would appreciate any thoughts!

Thanks