Don't ever soak your corks. You can dunk them in Kmeta or spritz them, but don't soak them. Most of us just use a corkador.
As mentioned, maybe you filled the bottles too full and with a little temperature rise, they are leaking. Between the bottom of the cork and the top of the wine, there should be a gap about the size of the width of two fingers. Much less than that and the cork will try to come out or the wine will slip passed the cork. (When you install the cork, it creates a compression inside the bottle. You can't compress the wine, but you can compress the air, so if no air between the cork and the wine, something has to give.)
It is also possible that since you didn't leave the bottles standing upright for a few days and the wine immediately slipped between the cork and the bottle, you never got a good seal.
By the way, what size corks did you use? #8 or #9?