I've come across a visual glitch that happens in the tool bar when Pixelmator Pro 2.0 is in light mode, fullscreen and has only one doc open.
https://youtu.be/CP_oGrN9RZU
Big Sur 11.0.1
iMac (Retina 4K, 21.5", 2019)
3GHz Intel Core i5, 6 cores
RAM 8GB
Radeon Pro 560X 4 GB
Spanish
(I'll probably use Pixelmator always in dark mode from now on anyways, because 2.0 light mode is awfully uglier than 1.8's: 2.0 is full of boxes, bars, separations, light and medium gray areas where 1.8 felt sleek and integrated. Thankfully dark mode somewhat conceals it.)