Neck hump at body and humidity.

 I'm trying to get a mental picture of how too much moisture would do this. It was probably all solid wood,

I imagine since it a nylon string guitar string tension wouldn't cause the top to sink in . If the back swelled at the same time then that might have created enough force to the sides because the back was actually wider since wood seems to swell across the grain much more than the length of the grain  to affect the top. Then classical guitars have a much different top bracing than steel strings.

 I only owned one classical is 1973 when I lived in IL , an Epiphone high end with a hard shell case. It used to get very humid in summer yet most of the year it was cold with the heat going .  I had three acoustics when I lived in IL and I never knew a thing about humidity I don't recall one music shop that sold any thing for guitars to do this ,I have no idea why I never had one issue and kept them in their cases. two were all solid wood the classical and a Gibson 12 string.

 With this Seagull I got in 2006 I still didn't know about humidity until 2009 . What concerns me most is I looked at all the braces best I could , all I have is a round mirror with a handle that extends yet the head can be tilted only if I pull it out and move it manually . There are better ones that I think one can tilt the head via the handle. Plus I use a small flash light you can focus the beam . I can see all the braces except the one cross brace under the finger board end , I can see the sound hole side yet the side facing the neck I can only see part of it. I see glue along both sides of all the braces yet on the neck side of the cross brace I don't see the glue line on the bass side and can't tell if it's a gap or not and that's the side I see the 14th fret hump . I don't see a twist in that brace and nothing that indicates it's loose . I know the glue didn't simply vanish . My best guess is it was always like this.

 I don't know if you ever saw the Godin factory tour where they should the braces glued and the placed in a machine under vacuum with a air bad to apply pressure . I don't know how long they have been doing it this way or if they missed to edge of that brace or if I can't see it well enough.

 The part that does trouble me is there is a tech near me who is well known , he does work for just about every well known player worked for Gibson in Tenn then moved here in the 70's and he's authorized repair for Gibson and Fender and Taylor . Point is I called him a while back 2012 and told him what I had and what I did and he said I should never have humidified it , he said here in Hollywood CA were have the perfect climate and don't need to do this. I imagine his idea is when the RH drops to 15% for a week then returns to 50% and some times 65% this balances it out and I realize most all hard shell cases are far from air tight and thus when it goes up to 50% it is an automatic slow humidification . I can under stand this concept , I just have a difficult time buying it. Plus it is a well known fact that wood has a mind of it's own and no matter what it changes and this can't be predicted . I've also read acoustics acclimate to their environment which can take several years before the wood no longer try's to go back to being a tree and  becomes a guitar . I have this Epiphone AJ-100 round shoulder dread all ply I got in 2009 new and have no case and over time even though I cover the sound hole to humidify the body it took a few years before  board shrunk and had fret sprout telling me it does get dry  enough long enough here. When I got the Epi EL-00 Pro I always keep it in the case and have a sound hole Planet waves plastic  removable sponge between the strings deal and a sponge at the peghead and it has not changed. It has a solid top and laminate back and sides like the Seagull I'm not going to change that routine . It was also 2 years old when I got it new in 2014 the seagull was also a 2004 model I bought in 2006 2 years old both were new.  It's possible I allowed the seagull to dry out then humidified it to many times and now it's permanent and won't come back , this is also something I've read. I've read a lot of things and a lot of opinions all differ to an extent.