I have a 2018, Tmax DX (with I guess too many bells and whistles now

It has run beuatifully for 3 months, both in almost freezing temps in March and hot summer now in May... but it's now in May it last week didn't want to start, not a single click from the starter, but full electronics/windshield etc working. After a few on-off cycles I got it started.
Today (5 days later) I was left dead on the petrol station after a fill-up. It simply didn't start. Again, all electronics working, TFT display, motorized windshield etc. The Tmax Android App did show battery charge level as 12.1V which is very low. So I charged it for 30min and got it to 12.7 (of course temporarily) but still, not a single click when pressing start.
Hmmm... is it really the battery, maybe all the amazing theft protection electronics doing spooky things? Since it seems to be 'digital', as no funny sounds or such.
Anyone else? Any opinions?
I'm having a trucking coming to get it to a Yamaha dealer tomorrow (as it sits there at the petrol station parking lot now)...
(looking in the app, under Device it does say, 'Device Status' = System armed and 'Under theft' = No)
sucks... I was so happy with it!