Yep, it's the famous "mobile radio active" bug.
Your detailed AquaMail screenshot (thank you) has for AquaMail:
- A perfectly reasonable "keep awake" time, 16 min, this is how long, total, the app actually worked in the background and kept the device awake
- A totally out of proportion "Total connection" time (how Samsung labeled "Mobile radio active"), this is Android keeping the phone's radio in a high power state long after it's needed, and attributing it to some random app (in your case, AquaMail)
The bug is random. May not happen, may happen with any app.
For screenshots of other apps, including Google's own, please see the FAQ:
http://www.aqua-mail.com/?page_id=227under Android 5+ and high battery use, 'mobile radio active'
The Google bug report:
https://code.google.com/p/android/issues/detail?id=165558Reported: Apr 14, 2015
Priority: Small
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