Yun glitch? (Arcade)

I’m rather new so if this is common knowledge, let me know.

Using Yun, the end of the first round ended with:
Jab, Short, Strong, Jab-Shoulder ((KO)) xx SAIII activates after KO.
At the beginning of round 2, Yun’s supermeter showed a charge of:

1/1 : + 1/10 meter charging

While it was showing 1 Genei-Jin in stock with 1/10 meter I figured to go ahead and just activate the super to see what would happen. Nothing happend. I charged the meter full and then tried to activate again. Normal result. After that charge was finished, the meter went back to normal.

Because this was something un-intentional and I have a 1/100 chance of doing it again on purpose, I just wanted to ask if you can explain the reason the supermeter showed +1 charge with another meter on the way. And why I lost the initial Genei-Jin charge at the end of the 1st round. It gives the impression that you can shock 2x Genei-Jin, but what acutally happened was I lost the first charge that I earned, resulting in having to charge another whole meter to get 1 SA off.