MATIC is the native crypto currency for the Polygon network. The Polygon network runs in parallel as a "sidechain" to the Ethereum network and is much faster for processing transactions.
CoinZoom supports MATIC only over the Ethereum (ERC20) network and does not currently support it on the Polygon network.
You can check the ERC20 blockchain explorers like etherscan.io for missing or delayed MATIC transactions.