Factorio Forums

How to reproduce:

• You need to have 2 (or more) labs with a wire connection and "set research" enabled.
• In lab 1 you set a conditional research technology with its condition fulfilled (1==1, or something like that) as top-level technology to research.
• In lab 2 you set a different conditional research technology with its condition fulfilled (1==1, or something like that) as top-level technology to research.

Result:

All your labs start flip-flopping between the researched technologies every tick or so, consuming science packs and seemingly not progressing the researched technologies at all.

Thanks for the report however this is not a bug. You’ve set multiple labs to change the research and so they are. Progress is applied correctly as the labs run.

If that’s not the behavior you want, don’t do that.