when he snatches things he tends to do it unexpectedly and runs and swallows them before you have chance to try leave on him.
Quick little blighters when they are young, aren't they ??
they lollop along and then suddenly take on a burst of speed when you least expect it
I just reinterate what I suggested before really - if you are busy and he has the chance to sneak up on you, then maybe you need to delegate someone to always be on puppy-watch when he is not crated, so he can't do it unexpectedly. He's obviously learnt that this behaviour gets your attention; and is great fun - the best way to break the habit is to prevent it happening rather than expecting him to resist tempation at such a young age
Its like having a toddler - you have to watch them all the time unless they are confined; I remember wishing I had another pair of eyes and two extra pairs of hands - I had a toddler and a pup at the same time
There are no magic solutions; patience, time and consistency - but personally I think that three veterinary interventions in 3 months is a lot for his little body to have to deal with