Help needed on using Loricraft PRC4

I received my new Loricraft PRC4 record cleaner last week, and have cleaned a number of old & new LPs with it. I found that on every record that was cleaned, scratch lines were left in the leadout groove area regardless of the arm weight used - I tried the suggested 2.5 grams, then reduced it to near 0 gram. Has any Loricraft PRC users encountered this problem? Any way to fix it?

Any help will be much appreciated. Thanks in advance.