We have been experiencing, for about a month or so now, a glitch where player's storage systems (Refined Storage/Applied Energistics 2) go offline if they have been in unloaded chunks for extended periods of time. They do not come back online without restarting the server, sometimes requiring multiple restarts.

The issue is caused by FTB Chunk Loader. It not keeps chunks loaded. Adding the Chunk Loaders mod and using its block to keep chunks loaded make all working as expected

I experienced something similar in single player. Everytime i go far from the base or in a different dimension the RS system goes offline (actually I'm not using ME). It's not something about chunk loading because the energy system is alive (reactor and cells).
I can see the RS system going offline with a receiver that shutdown in about 10 seconds. When I come back to the base the system is offline, like it was without energy, and come back alive in about 5 seconds. The issue affect Compact Machine dimension too