Just started producing flavonoids. It is made in a single biofactory and connected by a long series of pipes to a single research center.
I know that sometimes fluids will round down, but this is extreme. I've produced 1300 units, only consumed 50, and only around another 50 is in the fluid system. Over 1200 units have seemingly disappeared into the void. I've double-checked and there are no sinkholes or other outlets for the fluid. If links are allowed here, I made a reddit post with a screenshot of the problem.
https://www.reddit.com/r/factorio/comments/k7hj0z/why_is_this_fluid_disappearing/