I have two machines. One, a desktop, has been running for several years. The other, a new laptop. Both running current FF. When I load up my desktop, all app tabs are reloaded/refreshed. Laptop does not. Checking settings, I have toggled the "Don't reload until selected", to no avail - oddly, the desktop has this option *selected* yet seems to ignore this setting. Many moons ago, I recall a popup question on desktop asking if I wanted this behaviour, and I selected yes. It has dutifully done so ever since. Laptop has never asked this question, and has refused to comply in any case. Almost seems like there were two ways to switch it on/off coded in at different times and FF code points in two directions!