On the latest version, no edits to your control. Shift clicking on the fuel cell brings up the gui as usual, but selecting a different one and applying it does not replace the fuel cell like it did.

It also doesn't error.

that's weird I tested in my pc and everything is working

I'll try a fresh download.

Figured it out. In converting your hydrogen to Bob's, I neglected to change the fluid lock on all your fuel cells, and only did the tertiary one.

Sorry for wasting your time with my stupidity -_-

No problem