What is it about decals that one time they go on great and the next time all hell breaks loose.

Sorry for the rather long post.
Before I start, let me give you some background info on my prep work.
I have use Aviattic decals before with no problems.
I airbrushed the wings with Tamiya gray lacquer primer in the bottle followed by Gunze's Mr. Color Off White gloss and then shaded using Tamiya Smoke so I had a nice semi to glossy finish to start. This is my normal procedure which has worked for me in the past with no problems. I also used warm tap water and keep the dish on a coffee cup warmer while I decalling. I was sure to soak the decals about 15-20 seconds and then removed them to a damp sponge to loosen the rest of the way. After the decal is in place, I gently roll the excess water from beneath the deals using cotton swabs.
I started applying my Aviattic lozenge to my DVII's wing last yesterday. I do the under sides first and started with the lower wing's right side. The decals when on great and smoothed down nicely. I then did the top wing starting with the center section and continuing on the the wing tip on one side and they too went on with no problem.
Now here's where the trouble starts...I go to do the other side of the lower wing and I inspect my previous work and notice a good amount of silvering of the decal. I work slow enough that if the decal wasn't dry, it was almost dry. So I figure I add some decal softener to help it along. I have several decal solutions on my cluttered bench

but my first go to is Gunze Decal Softener. I applied some and saw no real reaction but I decided I'd let that dry and examine it later.
I then go back to continue on the top wing and the section in the middle looks good, but the decal section next to it is like the lower wing with a lot of silvering. Humm that seems strange.
Well... even after using more decal solvent and this time using Solveset which is the most powerful solution I have the silvering didn't go away. Needless to say by this time I was rather upset to say the least. I have pre-shaded the wings and now was thinking I would have to strip all of this off and start over from the beginning. I then had the bright idea that I would see if I could pull just the decals off using some cellophane tape. To my surprise, the decals didn't budge and I actually had to try several times to get the decal to release. The really interesting part was that the decal didn't rip but rather can off in one continuous piece like it was a film of cling wrap and once removed there was virtually no glue residue on the wings.
So I waiting for more decals to arrive and trying to assess what I could have done to cause such poor results in the first place.
Any ideals or advise I gladly welcome. Thanks!
Chuck