reselect: Performance regression in 4.1.5?

Upgraded and application from 4.0.0 to 4.1.5. We are also using re-reselect as well as defaultMemoize in several places as a more general memoization solution. A screen on our app is essentially unresponsive.

it seems like memoization is broken, as if I observe profiles in chrome dev tools with 4.0.0 and 4.1.5, when I click on a thing for example, all the sub items in a grid of items re-render, but in 4.0.0 this is not the case. all jest tests involving selectors are passing.

have there been any subtle pattern changes when folks have upgraded that are needed? I see some changes involving defaultMemoize but it seems harmless.

I have also tried removing re-reselect and using the new built in maxSize config options.

any insight would be much appreciated! i’m still working on narrowing down the issue, but wanted to ask. Was very surprised that it all seems to work except on one screen on our application that is very data intensive.