Hey all, been a lurker of TGP for quite some time but haven't posted much. I am having some tuning instability issues with my Gretsch Duo Jet that my wife bought me for Christmas. I took it to a local shop and had it set up for 11's and they intonated everything, checked the Bigsby, etc. and made sure it was all good. That was only a week ago, with brand new strings that don't have a ton of playing life on them, and the guitar will seriously just not stay in tune. The high E string will "pop" in and out of tune at times and the G string absolutely will not stay in tune for more than about 5 minutes. I have tried intonating the guitar, based on instructions from the included Gretsch instruction manual. Does anyone have any suggestions for what I can do? I will provide pictures when I get home from work today, but I am kind of at a loss for what to do. I have very limited experience in guitar maintenance as well, which is why I took it to a shop to have the new setup done. Any help at all will be greatly appreciated, thanks!