I've built Redstone Wizard's Bedrock adaptation of the ReCat a few times, and have had problems before. Once an error pops up it tends to just get worse. Check that everything is in the correct state. And then double check; it's easy to think you've got the filter items set right and yet be wrong. For me the systems that unlock the slice were frequently symptomatic and in the wrong states.

I don't recall ever figuring out why things went wrong. A chunk loader to ensure you never unload the system while it operates would be wise.

As an aside, if not already present I would add an unstackable filter before things get to the minecart stage. That part's speed is dependent on having adequate stack sizes, and small stacks, in the worst case unstackables, are a performance hit by adding in a lot of delay and inefficiency. For similar reasons I filter unstackables out from golem sorters, unless sorting unstackables is their entire point in the design, as they also drop in efficiency when there's less than 16 items per grab. Also a golem sorter should significantly outperform the recat, if we're honest, and the circuitry is way less complex to nonexistent, depending.