Awkward freezes topic

I found those sudden reboots happening on my device, XT1033 with ART unrooted running the single sim firmware. Everything was fine for a long time, but the last weeks its been happening. It simply freezes, no matter doing what going into a point that when I press the power/lock, the screen won't even turn itself back on, forcing myself to force-reboot in order to work again. I also notice that when it happens, the device has a downfall in the battery graph even tho not much was consumed and even losing a couple minutes on the screentime. I will embed a photo.

Maybe switching back to Dalvik fixes it? Or something else is the issue? I got no "weird" apps installed. Suggestions?

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