I transferred $500 worth of BTC from Coinbase to an online casino. No problems.
After several weeks of gambling, with a $48 profit, I withdrew the funds into my Coinbase BTC account.
I received a Warning notice from Coinbase saying that I need to use the correct network or I could lose my funds.
However, there were no options available when I made the transfer.
It's been several days, and all the money has been withdrawn from my online casino account, but I didn't receive it in my Coinbase account.
Usually on some leading exchanges there is a warning before you make a transaction where you are asked to double check before making a transaction whether the address is supported or not. Moreover, there is no screenshot that can be shown so that people can judge whether it is your fault or the exchange's fault. But in most cases the mistake is more often made by the user because they don't check first before making a transaction.
It could be as you said that you are not using the correct network because you mentioned there were no other network options so your transfer was not successful. The solution is to send feedback to the support team and ask them to double check the transaction you made if it was their fault.