Most of them do not stick inside the ears. I was referring specifically to a product made by 3M, which is similar to this:Not sure about this. I have like 6-7 brands and models and none of them stick inside the ears. Perhaps you have too much earwax and they stick to the wax.
3M Disposable Earplugs, Hearing Protection for Events & Concerts, Mutli-Color, 32 NRR, 4-Pairs
The packaging is different in Spain but those earplugs above, that are thinner at one end, get glued to the ear and pop when removed. I do not have wax. The earplugs get stuck due to the material they are made of.
These are the foam earplugs I use and these do not get glued to the ear: