Did I link my ea-account to my YouTube account correctly?

It is not your error, it is just poor programming causing it to not work sometimes. I am a prime example, as I got the rewards for Fc Pro open Day 1 on November 27th, and I got them immediately after watching the required amount as I went into the game right after closing the stream. Yesterday I watched 3 hours of the broadcast, an hour and a half of that time without any interruptions, so without leaving the stream, abd I didn't even get the 15 minute reward, let akone the 60 minute reward. I contacted EA support so we will see what they have to say about it. (I also checked before the broadcast that I was on the connected account on Youtube, and that the two accounts were still connected, out of caution knowing EA, and everything was showing as connected, bur this didn't stop EA)