Pond Skimmer Atlantic Water Gardens PS4600 problems

Does anyone know anything about pool skimmers?

My dog ate my Oase Aquaskim so I bought one from this review to replace it.

The problem is that it simply doesn’t work - the floating part, doesn’t float so it ends up sucking water but not skimming, if I hold it up a few mm it works great but once I let go it soon drops down again.

No instructions and I can’t find anything useful via google.

Perhaps you should ask the seller