There's currently some pretty bad bugs around generators and providing them rotation on 1.20.1
All of the following issues have been tested on a world only using Create & TFMG on default Superflat
TFMG version: 0.9.3
Create version: 0.5.1j

Issue 1:

When connecting a rotation network to a Rotor & Stator setup or generator block, if the network does not have the required stress units, the network will overstress but the generators will continue as normal and generate power (or at least indicate that they are and visually rotate)

• Here are some pictures from my testing
  
  

• The debug block readouts are as follows for each scenario
  
  

To Reproduce
Place down some large water wheels (less than would be required to power a generator) then connect the generator by either placing it or connecting it with a shaft/cog/etc

Issue 2

Relogging causes generators to double their stress requirement until the network is updated in the manor explained below.
When you reload a save, rotationally powered generators will double the stress they inflict on the network, yet read the same value (22,400su in the below example)

Before Reload

After Reload

And after disconnecting the rotor from the power source, the network still acts as if the generator is still connected (even if nothing else is)

The phantom stress units can be fixed by disconnecting the entire steam engine from the network and reconnecting it. I did so for the above example by breaking and replacing the encircled blocks below:

Steps to reproduce: Build a steam engine or waterwheels or other power source, then connect the power to a rotor & stator setup or generator block, then save & quit to title and reopen the world. The SU of the network will be doubled, and disconnecting the steam engine from the generator will revert the network to 1x stress from the generator, but will not have anything connected to it

Issue 3

Trying to power generators with waterwheels then relogging (same with issue 2) can cause visual bug with only one portion of the network becoming overstressed.
This one I'm not as able to reproduce, but the below picture shows the one overstressed shaft and the rest of the network opperating normally.

I would normally attach log files but this is easily reproducible and there's multiple log files involved from reloads, but I can get some for you if you need them.
I love this mod, but this it pretty game breaking. Hope y'all are able to get it working easily, best of luck!