Deficiency or excess?

This is a leaf that I cannot for the life of me figure out what is going on with.
Brug was in mostly shade earlier in the summer, moved to more sun a few weeks ago (til maybe 3 o'clock.) . Leaves have been getting an overall lighter green color than when in more shade, and now, over the past few days, this has appeared on 3 of the biggest leaves. Notice the tiny dry looking speckles too.
I fert with either Peter's 20-20-20 or special miracle grow 15-10-15, about once a week.
She lives in a container with pro-mix.
I have read the recent threads re:deficiencies etc, but my little brain is starting to smoke from confusion.
Any help is greatly appreciated!

Brugs don't hold their leaves forever. It is normal for them to have a few yellow ones that will drop off and be replaced with new ones. Don't worry, it's okay.

If they get too dry, a few days to a week later, leaves will yellow and fall off.

Thanks Shirley and Susie!! I feel so much more confident than when I started with brugs, but every time I think I've got things under control, something new pops up. lol
I was confused because the leaves are turning this color in a strange pattern, not all yellow, like I have had before. I was reading Judy's list, and my mind started running.....

Brugs drop leaves in the fall too, not all their leaves, just a few. Like Shirley said, it will grow new ones, some leaf loss is normal.