Chess.com used to have a massive problem with disconnections. Many players were left hanging for 5, 10, 30 minutes waiting for their opponents to come back. They changed things years ago to shorten the reconnect time allowed for disconnects.
Obviously, when you switch apps, you are losing your live connection. I believe that the allowed disconnect time is only 1 minute now. Frequent disconnectors get automatic resignations.
If you want to go away and come back later, why not play daily chess? Those games are often completed much faster than the time limits.
Previously if I had connection issues on one device, I would simply switch to another device without any issues. I would get the "logged on elsewhere" message on one device and continue playing on the device I last logged on to. If I do that now, I now sometimes end up losing the game "on both devices". I have resolved this by disabling the network connection on the first device or closing the chess.com application before logging on to the second device. That is not an issue now but I think it started happening because of some changes to the app which leads me to my real question:
I often play 30 minute games because I want to do other things while playing and sometimes I would be doing those things on the same device. For example, it happens that an opponent continues thinking for long on a move where there is nothing to really think about (I don't mind 'cause if I didn't want to wait, I would choose a 5/10 minute game). During this waiting time, one would want to switch to another application and do something else while allowing the opponent their time to think. However, when I check back later to see if the opponent has played, I would find the clocks stopped and no message on what has happened. At that point my rating tells me I have lost the game. My absence on the app for 3 minutes should not be considered as a disconnection, especially not on a 30 minute game.
I don't mind losing the points cause I am only playing for fun, but it would be helpful to know why I lost so that I can fix the issue if it is on my device or check back on the app within x minutes if it is part of the "flair play" mechanism. This is especially for playing on a mobile device (which for me is most of the time)
I use Android devices.
It happened for example in this game:
https://www.chess.com/live/game/2292502488
I was leading in material and a fairly good position. I was leading on time. I played and switched to another app. When I checked back later, I lost, probably for "fair play".