When you place a digital miner, it doesn't initially require any energy to run. You can define a filter, then start mining, and it will both display 0FE/t in the gui and actually require 0FE/t to mine and pull up items. If you toggle silk touch, change the radius/height, or add an energy/speed upgrade (basically anything that triggers the per-tick value to change), it will display the correct value, and shut off if not enough FE is available.

Breaking and replacing the digital miner reset the value to the correct one.

Steps to reproduce:

1. Install forge/minecraft
2. Place a digital miner, this can be done in survival or in creative.
3. Define a filter (I just used a tag filter of ore), then start the machine.
4. Observe the listed 0FE/t cost, and how the machine is still actively mining up ores.

Versions:

Forge: forge-1.15.2-31.1.74
Mekanism: Mekanism, Tools, Generators, Additions, all the latest (1.15.2-9.10.3.416)