yep silly bug
anyway try always to do 1k, 2k, 3k packs, so u can get that 0.1% bonus
ex: 1k sweat + 1k nexus = 1001 ME
if u need something extra for example 1354 ME then try 2 refining runs: 1000 + 353 ... it should work
btw this happens with any refiner, not only tt refiner