I only have one varigated flowering AV. It was healthy before it started to bloom. I had lots of brown spotted leaves. Are varigated ones weaker?
Variegated plants are generally not as robust as non-variegated plants. The light color in their leaves is caused by a lack of chlorophyll so the plants generally do not grow and bloom as much as their green counterparts. (This is very much a generalization; a lot depends on many other factors).
That said, I don't think your leaf problem has anything to do with variegation. Do you have pictures? It would help a lot to be able to see the problem.
I think it is because it is in a cold north window. But the purple ones right next to it are ok.
Z, Some variegated plants are very fussy. It doesn't take much to throw them off. Others are tougher. I have one with the same problem. Plants with variegation only on the leaf edges are sturdier than ones with overall variegation. You are not using water with chloramine, correct? Joanne
Update, it prob'ly was the cold. I moved it away from the cold glass