There's your problem....you coated with clear. The solid inks used for wet transfers do not need a clearcote before applying. That is only those "cheap" inkjet types.....
If you apply clearcote before the decal is applied it will become brittle and tear easily.

The correct technique is easy: Dip the waterslide decal into warm water real short (3-5 seconds). Place it someplace where excess water can run off (i usually place it on the edge of a dinner plate). While waiting for the decal to löoosen on the blue carrier paper, just coat the entire area where the decal is to be placed with Mr.Mark setter liquid. Then place the decal with carier paper over the wet area, and let it touch on one corner. slightly push the decal off the carrier paper on the edge touching the wet model.
Hold down the decal there, and carefully pull out the blue carrier paper so that the decal comes to float on the setter liquid. Then push it around until it is placed to your likings. Using a soft towel, push it down in the center, and begin pushing out the excess setter fluid from that point outward. When the entire decal has been pushed down, let it rest for 2-3 hours. Voila, a nearly invisible, large area decal. Largest i've done was an entire US letter sheet, came off and went on wrinkle and rip free.

Best of luck on your next (unpainted) waterslides :-)
Regards
Hank