A poor install, pure and simple !.
Why run the two sided tape horizontally for a start, and only in two staggered positions, what’s that all about ?.
School boy error.
Four strips of good quality two sided number plate tape evenly spaced vertically and then applied to a pre degreased number plate backing and the predegreased body surface contact points.
It’s not rocket ? science really ?.
If this simple method is followed, they will stick without any issues.
Have you ever tried removing a set of plates, that have been stuck in place for a couple of years ?.
OMG - You will be lucky NOT to break the plates, they are stuck that securely.
Usually requiring the help of a hair dryer or a heat gun set on low, to help soften the glue on this tape.
When it sticks, wow does it stick.
Like with all adhesive's the secret is in the prep !.
If you want something doing correctly, then do it yourself my Dad use to say ?.