Illustrator 25..0.1 on MacBook Pro 2016 running Big Sur 11.1

My toolbar does not allow me to access any of the other tools / submenues to change tools. Neither clicking the little triangle, nor hovering will open up the submenues. I can cycle through the visible tool icons by clicking while holding option, but have to open up submenues through Windw/... to get to tools / change settings. A real bother in my workflow.

I've tried reinstalling Illustrator, no avail. I also can't reset the toolbar - that option is greyed out. No difference if I use the advanced or basic toolbar.

I'd have to attach a video that shows... nothing happens. So didn't do that.
Really hope to get feedback / a bug fix for this.
Indesign and Photoshop feel much more stable in daily use than Illustrator :(