After 6 months of having the 20180124 because of the viewtopic.php?f=191&t=369542 problem, today suddenly the cpu is working on full speed with no reason and battery started draining fast. I made it through the day 8 hour shift by having wifi, gps and Bluetooth turned off when I used to return home with at least 80% battery. Any explanation? Yes, I made a reset when I installed the firmware and today also but cpu spy shows 0% of deep sleep.
Finally, which is the best version of firmware, the most stable and the one that makes this phone work as best as possible? There is always a different issue with every version!! Admin tell me now witch version should I install?

I suggest you to try the December 2017 ones, followed as always by factory reset.

So, we are going back from battery drain to sudden reboots...

I had a similar problem this week. Normally after 12 hours I have 50-60 % battery left. Suddeny the phone started to get very warm and the battery drained from 100 % to 0 % within 9 hours. Found out that an app that I even did not use started to drain the battery. Why? I have no idea. The app got no update since I installed it and made no problems the first months.

In my case it was the Paperang app, it's for a bluetooth thermo printer.