I've had a BQ Aquaris M4.5 phone with Android 5.1 for months and have never experienced any problems. However, since last week and without having changed anything that I know of (and not having installed an update from WhatsApp), my phone sends the message before I finish writing it. I can only write one or two letters before it sends the message, without me pressing the send button. It continues doing this until I close the app and open it again, but it happens dozens of times throughout the day and I have no idea why. I have erased the cache, used cleaning apps to clean the phone, etc., but nothing solves it. I installed yesterday the latest update and the problem seems even more frequent now. I have searched online but I can't find users experiencing the same problem.

I've thought of doing a factory reset for my phone, as I would like to do it anyway for general cleaning. However, if I have a Google backup and another backup on my SD card, will everything be exactly the same when I restore the phone? Will I actually clean it?

Thank you