Truck transmission problem any ideas

Yesterday accelerating with my 2007 yukon 5.3 gas vehicle it made loud banging noise from back and would rev up and not move, thought the tranny blew up. Put in 1st gear and power returned to move so thought I would try and limp home but found that the truck would run fine if shifted manually and once up around 40-50 could shift back to automatic and would upshift into the higher gears. Had to stop for stop sign and truck again just rev up and not move in auto setting. Started progresion manually in 1st and would shift fine to speed and could again put in auto and drove home no problem. Checked tranny oil and good. Thinking it is a control issue and tranny is still good as truck runs fine when manually shifting. Anyone else run into a problem like this or ideas what it could be? Sucks as pheasant trip is now on hold.

I’m no mechanic, but it sounds like a shift modular to me, Normally easy to get at and cheap to replace.

Thanks that sounds like a good starting point to try before bringing into shop.