So here's one that made me furious.
You've got a Tab open, do something else on the PC and Chrome decides to trash your open Tabs. Tabs need to reload when chosen.
It's a bugger and affects some tasks where the Tab/Browser needs to stay open.
To avoid this from happening do the following:
Enter chrome://discards in the address bar. Toggle the switch of Tabs you don't want discarded.

You've got a Tab open, do something else on the PC and Chrome decides to trash your open Tabs. Tabs need to reload when chosen.
It's a bugger and affects some tasks where the Tab/Browser needs to stay open.
To avoid this from happening do the following:
Enter chrome://discards in the address bar. Toggle the switch of Tabs you don't want discarded.