Pretty straightforwards. I know you can't upgrade the research lab while you are researching something, but I can upgrade a different research lab on a different planet. Maybe this is intentional but I thought it was worth pointing out.

Research is global. You cannot upgrade any labs when you are researching.

Well, then there's a bug, because when I'm researching something I can still upgrade any labs that I did not start the research on.

Correct me if i am wrong but here is my understanding of how this works.
Any lab not included in the Intergalactic Research Network (IRN) can be upgraded during research. The colony that initiated the research and any lab included in your IRN will be unavailable for upgrading for the research's duration.

Overdose nailed it.

You can only start a research on a lab that meets the required lvl of lab and is not upgrading.

You can still upgrade any other lab by upgrading it before starting a research. The research time will be the same as if the labs in the IRN are not upgrading.

You cannot upgrade or build any lab when research is ongoing.

Hello Zorg.