I’ve found in the last few flights that even if you set the interface timeout to never the interface still timeouts after a period of time. This usually happens after around 30 minutes without screen interaction.
IF version 16.06.1
How to replicate:
1:Set a FPL longer than 1 hour with AutoNav on
2.Have all graphic settings on low with low aircraft count
3.Have interface timeout set to never and hide status bar option off.