What I have already seen happen is the user claiming, and the first claim was successful, but he (forgets/gets confused/thinks the first claim was not successful) keeps trying to claim again and again, and to ever diffents seeds, and (as the first claim was already made) the following claims won't happen again.
I saw users claiming to a seed and looking for the balance in another seed.
Please check all the seeds you have, maybe your balance has been claimed to some other of your seeds, then you are looking for your balance in the wrong place.
The claiming procedure is "dumb" it does not know if your claim has been already made and if so, where the balance was sent to: it only knows that "the pre-claim seed has a total amount os iotas".
I have seen identical situations, and in the end the user found out that his issue was caused by his own "confusion" regarding his seeds and, at last, his iotas were safe.