Since nobody else has jumped in, I'll offer a best guess: I would check to see if maybe the roots are rotting. Your situation sounds more like what my Philodendron 'Autumn' was doing before I discovered it had no roots left than anything else I've seen a Philodendron do.

My backup guess would be that it's too cold (I wouldn't let it get below 60F/16C), though the two problems can obviously overlap and make one another worse.

Richard, Red Congo needs bright light. Not necessarily direct sun. Espeically during summer months.
My Congo lived in a south window, year round, for years, but between a neighboring house and fir tree, strong rays obstructed. Still its color remained red.
Humidity is mandatory for Philos, so if your home is dry. add a humidifer, and spray/hose leaves.

Repotting shouldn't have been done, since it lost leaves, (Sick/weak plants shouldn't be repotted) and possibly dormant, a debatable topic, (some plants do, others don't) Philos are evergreen, leaves should remain in tact throughout the year.

Since your soil stayed moist two weeks or longer, it was 1. Too heavy, or 2. Over-potted.
What size/material pots, before and after repotting? Is it doing better, worse, the same?
You mentioned it being a 'little rootbound.' What is a little? How much space between rootball and inner, old pot? Toni
PS. Do not fertilize unless plant resumes health, and new growth forms.

Yes, ourhouse is on the dry side, i will mist it along with the other plants I repotted it in the same pot, the pot is about 2" larger than the root ball, the roots are all wound around in a circle. I should have knocked all the dirt off the roots and inspected, but didn't think of it at the time. But handling it the little that I did, i don't think any were mushy or anything. I've moved it to a brighter, warmer room. No more leaf drop, still have those 3 leaves but they're droopy. I can't understand why it stayes so moist, maybe the drainage holes, plastic pot may not be the best. Thanks for all the help!!

Richard, clay pots are the next option, but if anything, your soil is staying wet/moist because of its type.
I doubt it's a pot problem..either the soil is heavy or you're overwatering.
Set your philo in a bright spot, away from a heating source, and let it be. I allow soil to dry completely, but it's recommended soil remain moist..moist not soggy.
Turn up the humidifer, if you want to spray, fine, or wash leaves with a soft cloth, that's fine, too. But for the time, 'try' ignoring..lol..it sounds cruel, but sometimes a little neglect does far more than being over-protective. Toni