Motorola v525 has software problem, all models before 19.01. has somekind of
software errors. I didn't have problems like you, but I had problems with
mp3 playback and last before going to service was that I Couldn't power on
my v525.
I got new software and it appears to work properly. But I'll know for sure
in a week time.

Good luck

Try to put battery saving mode offf, i read somwhere that it colud make a
difference, i did it with my v300 the day i got it and it has never turned
itself off. Also i read that if you put colour scheme to Jade, it stops
sudden switch-offs while browsing your mobile menus for a longer time.
Hope it helps

The first 500 I had was the same. If you left it for a minute or so without
pressing any key it switched itself off whether the phone was left open or
closed. I spoke someone at Onestopphoneshop who said early 500s (and by
extension 525s) were faulty and that it was 'something to with power supply'
He advised me to return it, and the replacement has given no trouble.