There can be several reasons why funds sent to your Trezor didn't arrive. Let's take a look at the most common ones.
First, please check the txID (transaction ID, hash) of the transaction in question on the blockchain explorer of the specific cryptocurrency you used. If the transaction is not confirmed yet (i.e., still pending), you need to wait for the first confirmation.
The time period of the first confirmation is related to transaction fee that you chose to pay while you made the transaction. For more information on transaction fees please see this article.
If you want your transaction to be confirmed faster, you can speed it up with Replace-by-fee feature. More information can be found here.
Make sure you are in the right wallet. You can verify this easily by checking if you can see the address that you used as receiving address listed under the addresses of a specific coin account in Trezor Suite.
If you can't see this address in your wallet, it is most likely because you are accessing a different wallet. Make sure you have the right recovery seed stored in your Trezor and you are using the right passphrase for the wallet you want to access.
Are you sure you sent your funds to an address of the correct coin? Coins should never be sent to addresses generated for other coin types, as this may result in the loss of funds. If you suspect that your coins were sent via the wrong network. Learn more about what you can do to retrive them here.
This is related to Ethereum and Ethereum-based coins. If you sent your Ethereum to Ethereum address which you can see in your wallet, plus the transaction is confirmed and you still can't see your funds, you most likely used another network when sending your funds.
Trezor Suite supports only the Ethereum network and this is the reason why you can't see the correct balance there. However, Trezor firmware also supports many other networks such as Polygon, Arbitrum, and Binance Smart Chain. You still own these coins (as you own private keys for the address that includes them), but you need to use 3rd party wallet to be able to display these coins on different networks. There is also the possibility that you can retrieve them back to the Ethereum network. More info here.
More information on how to use EVM compatible chains with Trezor is available in the following video:
In case there is a pending Ethereum transaction with a lower "nonce" on your Ethereum address, you can't send any other transaction from this address before the one with a lower nonce is successfully confirmed or cancelled. You can find information on how to speed up or cancel pending Ethereum transactions here.