Welcome to the forum Rjdemy!
Ugh, that does sound frustrating. I haven't played around too much with the dual mode. I'd try switching it to manual to see how it works. Looks like you've already tried charging it, that's something else I would've tried. Normally batts start acting funny like that if there's been any type of moisture introduced into the button area. If nothing seems to fix the issue I'd recommend contacting CS for a replacement. I believe the DM Zeus has a 1 year warranty on them and they may have other suggestions as they may be more familiar with this issue.
Best of luck! Let us know if you have any more questions