I too had a scots pine with wilting shoots,during the day they would wilt and overnight would recover.
This amused me for awhile and i imagined that since it was recently potted on it's uppermost shoots were not getting enough sap,i speculated that as the roots recovered so too would these shoots and that growth may even have been redistributed because of it.
It was after that i noticed the blackfly infesting the shoots,these i sprayed with insecticide and as they died and dried i marvelled at their throes of death.
Sill it was wilting only now it was not recovering so i examined further and found a depressed band of bark girdling the stem of the ailing shoots,this was the width of the price tag that i had removed earlier in the year.
Nothing for it but to remove the apex below this and examine it more closely.
The bark was squashy and the wood beneath the bark whilst not rotten was indented.