Allowing productivity on items like long inserters and combinators changes their rocket capacity to some absurdly large number of stacks. This is an issue that affects other mods that allow productivity on non-intermediate items.

The reason this happens is that the game code which calculates item weight (and therefore rocket capacity) considers if Productivity modules are allowed on the item as a shortcut for deciding if an item is an intermediate product or not.

This was reported as a bug on the forums but Rseding91 marked it as "not a bug," despite Productivity unintuitively being a factor in calculating item weight.

Another user on the forum, warbob5000, has dug into the code to find out how/why this calculation occurs and has provided example code that can be used to re-set the weight/rocket capacity of items after enabling productivity for the item recipe: https://forums.factorio.com/viewtopic.php?p=642941#p642941

As far as I know, none of the productivity mods have tried to solve this, yet, so please consider implementing a fix for this issue based on warbob5000's solution.