Oral sex help 😩

So me and my bf have been together for a little over a year and I’ve been struggling with giving him head properly. IVE NEVER HAD THIS PROBLEM BEFORE. He’s explained to me how but it doesn’t process sometimes because when I try it , it still doesn’t always work. It became so discouraging that I slowly stopped giving him head and he understood as to why. I usually preferred to give him head in the middle of sex due to that issue. (I know it’s not anything bad as to why it’s not always working or anything I know he’s into me) he even told me that certain ways a female would give head it doesn’t work for him. Does anybody have any ideas or recommendations because I’m at the point where I don’t even want to ask him if I’m doing it right while I’m doing it because I don’t want to throw the vibe off.

Side note - only time there’s a struggle is when I try to give him head while he’s sleep or just soft and I try to get it up myself to please him a little more. ( BTW HE LIKES TO WAKE UP YO ME GIVING HIM HEAD)

Please don’t be rude, every man is different so bare with me