Oncidium Twinkle new leaves yellowing

[Michelle15]

I've had on Onc. Twinkle for several years, the first 2 years after purchase it did great, bloomed each spring and grew well. Last year I repotted it and I did not keep up on watering and I let it get very dehydrated, the pb all shriveled up and I did not get any blooms this year. So I repotted it again, cut out the dessicated roots, and started to water better. The good news is that the pb have all plumped back up, I have several new growths and new roots forming. The bad news is now I am getting newer leaves yellowing (not the old leaves just new smallest ones).
It is potted in a small/medium fir bark mix labelled for oncidium type orchids (from local orchid nursery). I have it under LED lights where it did fine in the past. I get occasional burns on the leaves if not careful. The current temp in my house is 68 - 70 daytime and 65 nighttime with humidity in the mid 40s usually. I do have humidity trays.
I have been using rain water with Green Jungle Orchid Fertilizer each watering with a water only about once a month. I have not been letting it dry out since that was the issue before, watering about once every 5-7 days. Maybe too much water? I thought it was a light issue but searching the forum it seems like a watering issue. Should I let it dry out more?