Mediterranean Palm in pot- new leaves suddenly turn white

[Canuck]

Hi! Purchased a few Mediterranean palms and getting them climatized to the garden before transplanting. They’re sitting in the sun, average temperatures these days is around 20C. After two weeks, suddenly new fronds are emerging white on one palm and quickly shrivelling up. Thankfully, the newest and smallest frond on this plant is still emerging green. Did I overwater? —- I’m guessing I did.  Or could it be something else? Should I cut these leaves off, or leave them alone? Side note, there was a scale insect infestation from the nursery, I already fumigated it...but I doubt that is what’s causing this issue.