Advanced colour options missing from callout value.

I'm soooo close to publishing a report and I have conditional formatting rules written for a number of card visuals. A stakeholders wants the rules amended slightly but for some reason, the advanced colour options button is missing from every single card in my report.

Here's a screenshot showing I have the advanced options for the category label but not for the callout value. Instead, it says that the colour for the callout value is fixed which is wrong because testing proves there is active conditional formatting on all of these cards.

Even creating a brand new card isn't working as the options button is missing everywhere.

Closing/reopening, logging off/on has not fixed this issue. Has anyone seen this before and knows of a fix?