FG version HIGHLY configurable. Adds a productivity research for every recipe that supports productivity and does not already have one.
Mods introducing new content into the game.
Furnaces, assembling machines, production chains.
When the first research is finished it instantly completes all 30 levels for the research
Do you have this mod? https://mods.factorio.com/mod/simultaneous-research Or anything like it? That is a known issue with that mod messing up infinite researches.
