Airy Fairy

There could be a few reasons behind that, so here are the most common reasons and some tips to help!
Prep: Make sure you are pushing back your cuticles and buffing with a rough buffer (included), not one that smooths your nail. The last step of prep should be wiping your nails with the included alcohol prep pad.
Glue application: The right amount of glue, with no flooding around the edges, is so, so important; too much glue is just as bad as too little glue.
You aren’t curing long enough: Make sure all sides are secure by curing the entire hand again for 60s, to make sure the glue is fully hardened.
Nail application: Do not move while holding the nail as you’re curing, as this could cause bubbles.

This process could have a learning curve for sure! But the perfect amount of glue is dependent on the size of your nail bed.
PRO TIPS:
Apply glue to the bottom 1/3 of the pre-buffed area of the nail, a little bit above the cuticle edge
Do not press so hard when applying the nail tip; stop right when the glue reaches your natural nail edge.
If the glue does not cover your entire nail bed or you see bubbles, take off the nail and apply more before curing.

Clear nails only need 60seconds to cure, but the sheer design nails must be cured at least2x. If you feel you used a thick layer of glue with a clear nail tip, werecommend curing twice to make sure the glue is fully hardened all the way through.