My fairly new DA5 only works from the wall wart, it will not run from the batteries ( I tested them with my multimeter, they are good)

Has anyone else had this problem, or is there a trick I don't know?

Fender 60th Anniv MIM Strat (SD Little 59er Br)
Agile AL-2000 Rootbeer Flame (GFS Vtg '59)
Fender Hot Rod Deluxe
GFS Chorus
What setting did you test them with?
If you only tested for voltage, you won't have gotten an accurate reading. If your meter has a specific battery tester setting, then you've got a problem with your amp.