Hello JoAnn, firstly this business of cutting back to a node. I tell people at orchid shows to do that but only because most of them are only buying the plant as a cheap bunch of flowers.
I am just about to cut a spike off at the base because the blooms have been out for three months and i want the plant to put some effort into growing some new leaves.
If you look at the Phalaenopsis Hybrids at orchid shows you will be hard pressed to find any blooms on secondary spikes.
Despite what some vendors will tell you Phalaenopsis are difficult and you need to adapt culture according to where you in the USA , maybe something in your summer growing conditions is causing the buds to abort. You didn't say exactly but i am assuming that all your other Phals are fine.

Well, I'm not an expert, but my little bit of experience is quite the opposite of a problem to yours - mine won't stop blooming and tend to hang onto their blossoms for months and then as they finally start to wane, out pops a new branch with buds on it. I posted this in another thread - I'm getting a bit desperate to re-pot 2 of them. They've been nonstop blooming since November.

I think you're still mothering yours too much. I tend to neglect mine - although now in retrospect, perhaps that's why mine won't stop blooming and rest for a while! Hmmm.

I find the Phals easier than my hoya to grow - which I had to nurse along for 20 years before the thing finally bloomed for me and now even its going bloom-crazy.

Once in a while I happen to notice the Phals are wilting and then I'll quickly zip some water into them and that's about it. Half the time I forget to fertilize too.

I have 1 phal that is in bark medium, 2 are still in the moss pots that they came in from the store. The 2 that are in clear plastic/moss pots, I watch the water dribble on through and come out the bottom and then I stop. The one that is in bark, I dunk the pot in a bowl of water right up to the brim for 30 minutes, then lift out and stick back in the window... maybe once every 2 weeks? In between I might dribble a 1/4 cup worth of water into it if it's been particularly hot/dry weather. Maybe that's just my bunch, but they don't seem to care one way or the other. I never mist mine either.

That all being said, my orchids live with a large number of plants in a very large picture-bay window that has a curtain covering them at night so it can be rather naturally humid in there. The phals sit in an east-northeast portion of the window and get about 4-5 hours of morning sunlight dappled through blinds.