Hello, this is going to be a very detail-lean issue as it is mostly my suspicions and I haven't found a way to reliably reproduce it.

I have been occasionally running into a bug where hoppers output items into what seems to be a nonexistent container, or are just backed up even though the block they are pointed into has space. I first ran into this with two hoppers feeding into a shulker box from opposite sides while developing a custom loader. One hopper worked, when two were added (most of the time) only items from one of the two hoppers went in, the other items moved or were stuck. Breaking and replacing the affected hopper would correct the issue, and possibly reproduce the issue with the other hopper.
I broke and replace every related block in that contraption and could never get it working reliably, so I ended up going in a different direction.

More recently, I had a hopper collecting mob farm drops pointed into, I believe a dropper, and I noticed that the items seemed to be disappearing. I think it may have been faster than normal hopper speed, like if a second hopper was below the first, OR similar to the behavior when a hopper inserts items into a wool hopperCounter.

That made me start thinking. I have carpet on this server and do have hopperCounters enabled, they aren't required, but it got me thinking, I wonder if there is some conflict or issue where the hoppers are somehow seeing phantom containers, maybe hoppers, or counters, and the items are being removed from the effected hopper and simply vanishing.

To be clear, I have no hard evidence, logs, nor a way of reliably reproducing it. I don't know if it's even carpet. But I know the behavior has been happening, and it somehow affects hoppers.

I'm going to turn off hopper counters for now, it's not like I need them on the server. If I see the issue again with them turned off I'll return and update this issue.

Sorry for the vague report, I just wanted to report a vaguely potential bug report in case anyone else runs into it.

Are you using Lithium? If so, which version?

@CommandLeo I am using Lithium-Fabric v0.10.0 for mc1.19.2.

@GrahamJenkins update it to the latest version (0.10.4 currently) and check whether the issue still occurs.

@CommandLeo Thanks, will do. As mentioned before, reproducing is unreliable, but I'll post an update if I see it again.

I see several hopper related changes in Lithium for versions 0.10.1-0.10.3. Appreciate the pointer, I'm going to close this as (suspected) unrelated to Carpet. Again, thanks for the off-topic help @CommandLeo, I appreciate it.