Moralis NFT endpoints report onchain data for the requested chain, address, contract, and filters. A marketplace can display a different number because its interface may include offchain listings or inventory, apply its own filters, or combine assets from several networks. Indexing or metadata timing can also affect what you see immediately after a transfer.
First compare the same wallet, contract, chain, and token standard. Then check the token's onchain owner and transfer history with the current NFT API. Query each relevant chain separately and consult the supported-chain list for the endpoint you use.
If an onchain token is still missing, send Moralis support the chain, contract, token ID, wallet address, and transaction hash so it can be investigated.