Not to mention that the presented error message shows $new as being ACCTGG.fq, and the OP asserts that it is LA01.fq. Incorrect/incomplete reporting of error messages and other results makes remote diagnosis an exercise in clairvoyance.

...my crystal ball is still in the shop. (It kept reporting "line 42".)

...roboticus

When your only tool is a hammer, all problems look like your thumb.