Is enemyshield in a container with Enemy ?
If not, Enemy is unreferenced (not picked) in event 425. So all Enemy get marked as picked.
Same for PlayerSelect, if there are more of them. In 428.
If they are in a container, it could work. Difficult to debug with a screenshot.
I would use containers, for sure. Then (i think, from my head, so untested). Combine in one event.
Conditions:
Enemy = visible ?
Pick nearest enemy to player position
Actions
Set enemy instance variable 'CanBePicked' to true
To pick with the mouse
Condtions
EnemyShield clicked by mouse (must be in a container with the enemy)
Enemy 'CanBePicked' is true
Actions
Enemy set picked
And ....
Condtion
Enemy is picked
Action
set playerselect (if there is only one) to postion of enemy (or shield, i have no idea where you want it)
set playerselect visible
Else
set playerselect invisible