Default [Q] Youtube on i9505 4.3

youtube on my i9505 loads to much on youtube app & when i open any video from browser although i had the i9500 befor but it dont loads like my i9505 now , also i have S3 i9300 & S2 and it works perfectly with youtube app and on browser and all of them was on the same internet connection and same router
what is the solution ??? & sry for bad english