RAM may be vulnerable to high frequency row hammer bit flips

I am running a file server at home with 4x 8gb DDR III memory

(Corsair XMS3 CMX8GX3M1A1333C9).

I had problems with one of these, where memtest86 reported over 500 errors in the first 90 seconds. I had it replaced, and now I have this problem:

Running memtest86 on all four sticks together I get one error per pass (during test 13, row hammer test). So I ran memtest on all the sticks individually. All of them go through four passes perfectly. Except the new one I got. On that one, I get one warning per pass, saying "RAM may be vulnerable to high frequency row hammer bit flips". Also on test 13. But no errors.

Since it produces errors when run with the other ones, and it clearly is because of this stick (tried it in different slots etc), is this covered by the warranty, even though it "only" produces the warning on the individual test?