The dissolver does not seem to have a fixed input slot when inputting directly into it. Tested with other pipes such as PipezMod, AE2 and RS. When inputting items into the dissolver the processing input as well as the output slots are filled with the items being inputted.

Which version of the game and mod? Do you have any images you can share?

Graphite goes output slot :(

Alchemistry 1.19.2-2.2.3
ATM8 1.0.6b

Ok thanks for reporting this. I don't know why that's happening as of now. The output should be invalid for any item to be inserted. So I'll have to look into it when I get a chance.

This should now be resolved with the sided configuration PR.