I have had the same problem for a while now.
Every now and then, I clean up the inventory of my heroes by equipping good items and selling junk ones.
I do all heroes at once.
EVERY goddam time, the game disconnects when I’ve finished with my 3rd or 4th hero, it doesn’t take into account my previous actions, so I have to start again from scratch.
That happens on both my devices, iOs 9.3.2 and Android 5.0. That happened before the 2.5 update and keeps going.
Am I the only one to face that?