Just installed Mint 20 and all is well except having installed Cairo-Dock and clicking the initial GL request and asks for the GL confirmation every time I log on. This never happened with Mint 19.3.
I installed Mint 20 onto a fresh partition, the laptop is same mid-range dell 3 years old and I have installed codecs etc.
I found cairo-dock a bit resource hungry (and prone to crashing) so I went for plank (when I found it in elementary OS about 5 years ago)… I still use plank…
plank won’t run in wayland however, is cairo-dock the same? you need to ensure you’re not using wayland compositor…