Hasn't YouTube been an issue now for like 6 months? All people i know have had issues with YouTube for a while now. It doesn't matter what phone or ROM you're on. It eventually works but sometimes you can be in a strong signal area and even on wifi and have to click retry like 4-6 times, sometimes more, to get it to work. It sounds like you're having a harder time but YouTube has still been crap for 6+ months now.
T-Mobile 32GB - Rooted Wicked v5 (TWRP 126.96.36.199)
Galaxy Note 10.1 32GB 2014 Edition
Galaxy S4 (VZW MDK) sold to pay for my Note 3
Droid Bionic - Traded for Note 3
Droid X - Now a WiFi phone.