I don't know, but it happens to me occasionally too with a 'Moonlight' philodendron. The theory that seemed most likely in my case is that I was letting it get too dry between waterings, but I've never definitively proven anything.

My banana does that when I bring it in and it does make a mess like purple stated, mind would drip alot at night,so first thing in the morning I would dry the leaves to stop more dripping.

I have a LOT of stalled maples right now that are just starting to move with the coming of some recent warm weather. We had a week of temps in the 80s & low 90s in early - mid March that got my deciduous stuff pushing so hard I had to take a week off to do repots. After the repots were done, it turned cold again and everything just sat there until this past week when we finally got some warmer nights & days in the 60s. Remember you're on tree time and that they're reactive organisms. Over-watering usually results in a typical drought response, which includes burned leaf edges. Frankly, over-watering isn't going to affect first flush much anyway. If you pruned off a few branches & stuck them in water, you'd still get good leaf-out. The energy leaves use for that first push is stored as starch/carbohydrates at the base of the buds. All that's needed for branches to push the spring flush is water & temps warm enough for growth, which can actually be accomplished absent the roots. I'm not saying over-watering is nothing to be concerned about - it is. It's a significant issue for containerized trees and should be avoided. I just don't think it's responsible for the stalled growth. Al

I agree, herbicide drift. 2-4D can volatilize into a gas and travel far, into the miles if the conditions are right. Your neighbor might not care, but what about everyone with in a mile of you? Don't tear them out, water well and keep them well fed and they will come out of it. They don't look hurt too bad. Jay