2017 Subaru Outback continually not starting

[Cindybug56]

I have a 2017 Subaru Outback and have had very few problems with it up until now. For the past few months, there's been an issue with it not starting. Had the battery checked, they could find no problem. Bought a new battery anyway. Several weeks later the same problem, a dead car. So we had a new starter installed, which seemed to fix the problem but then once again, dead. Of course, this happens shortly after the 7-year warranty has expired. I'm at a loss for what to do. I'm so frustrated I'm tempted to trade it in.