Hi all thanks for all your replies, as this has been bugging me slightly as to what could be happening!
Its happened to a handful of my clients, the first time i thought maybe onycholysis, but it started to happen on different clients.
I decided to put a set on myself and again ... well literally after a 8 hours it started to appear.
So it couldnt of been free edge that quickly, then maybe thought pocket lifting, but it didnt appear to be lifting after i filled down to the area.
The way i describe what it looks like, is adhesive that almost looks dried below the tip.
Ive never come across this before until i used NSI, And also used their tip glue.
So determined to get to the bottom of this, I applied another set of gels using creative gel bond, and ....... i didnt have any problems whatsoever.
Im prepping correctly, bonding, filing the tip etc, So oddly could it well be something to do with the NSI glue?