Good day. Like you, i JUST started myself ( literally within this past week ) and I'm having the EXACT SAME problem with my middle finger. I do have fatter than average fingers and like you, i tend to mute out the string next to the one i'm holding. Was thinking of trying to tape up the first knuckle with electrical tape with the tip sticking out and see how that goes. Haven't seen ANY advice with taping up fat fingers so i guess its not a thing. I'll post a follow-up after the experiment.