I am unsure whether this is a bug in Modular Machines, or one specific to the EnigTech 2 Expert modpack. As such, I will submit it to both githubs.
Modpack/Version
EnigTech 2 Expert 1.3.1
Can the issue be reproduced?
It occurres when I didn't input enough energy when machines are working and maybe other times.
Issue
After I notice I didn‘t input enough energy to the machine, I started the electric generator,but the energy input hatch can't accept energy correctly,like this:

(As you see I'm a Chinese player,so please ignore my possible grammatical problems,thanks. )
It should be noticed that sometimes reload the game may solve the problem momentarily.
Pls fix.