Minor bug since the following behavior seems to be affecting only one entity in the Realistic Fusion mod, WIP antimatter section. The matter-antimatter annihilation reactor does not have a % indicator. The mod author is working on an overhaul 2.0 version of Realistic Fusion, but I wanted to let you know anyways.

Can you upload a save game somewhere so I can take a look?

Alternatively, mouse over the reactor and hit Ctrl Shift F to bring up the prototype information and screenshot that?

Here's the debug screenshots
https://ufile.io/f/mtgjy