If you right click a sieve to see the interface while it's in the middle of sieving an item, it will start at 0 progress. Leave and re-enter the interface and it will reset again. Tested in single player.

This is not happening to me. What version are you on?

Happening to me too. Playing mc 1.12.2, mod version is 3.0.26.

Environment is Windows 10.

Playing "Stoneblock" modpack

Tested on StoneBlock, still working fine for me. Do you have exact steps to reproduce?