C41 Problem - completely clear film

I have had a problem developing some C41 films with the Tetenal kit.
I don't do large volumes so I get the Tetenal 1L kit and mix it as 500ml batches.
I developed some 5x4 film last week and it was fine.

I wanted to develop three 120 rolls in my Jobo but I thought that this would need 600ml of solution to cover so I mixed 500ml fresh developer and added 100ml of the old.

The films came out completely clear. No branding on the rebate or anything. I'm trying to figure out what I did wrong. I've never had anything like this before.

Could it be that I topped up my developer with blix by accident?

I'm only relieved that I couldn't remember what the hell I had on those films so I don't feel a great loss

Thanks in advance for any responses,
Marizu

Blix would totally kill your developer for sure, even a few drops would do it and 100mL would for sure. Obviously you should pour this batch out and start again. Sorry about your luck.

I always mix up the the entire 1L quantities and keep them in their own bottles. I reuse them many times, pouring the used solutions back in the bottle.