Fonts automatically changing to a regular style

Example of the issue I'm having:
I have a paragraph box with text in it, it is set to an Extra Bold character style. When I type new text into this paragraph or change any existing text, it will automatically change to the new text to a Regular version of whichever font I have selected. Additonally if I type any text directly onto the document it will change the colour to black regardless of what I have selected.

This suddenly started happening a couple of days ago. I have tried resetting my preferences, didn't work. I've even uninstalled Illustrator, deleting all preferences and then reinstalled the app but it still keeps happening.

Any help would be appreciated, I cannot figure the issue or find a solution.