Kids Wall Borders I Just Hung Self Adhesive Wall Border In My Kids Rooms And It Started To Fall Down Within The First 2 Hrs!?

I just hung self adhesive wall border in my kids rooms and it started to fall down within the first 2 hrs!? - kids wall borders

I recently finished painting the bedroom of my daughters and put its limits last night. They are the same type of stick and I have never used. I followed the border and do not touch more than necessary and not really to change the position of all. I went into the first room check was done after 2 hours and the border had fallen in the middle of the room! To avoid any risk, I stayed in a few places in the next room. I ran away from the border before it is finished, the hand against the wall. I was dangling over 4 feet.

My husband has suggested a hair dryer to heat up, but what can keep it better? And when it comes back on, which is my best option for an alternative to hard?

Please and thank you!