Sent Ether from Meta Mask via Matic Mainnet and the fund is missing


I am a newbie and I would like some advice. I use Coinbase and last week I tried to do the liquidity pool so first I connected the Meta Mask to and used the bridge to transfer around 0.4ETH to Matic Network, then I went to But the wait time was took long so I decided to move the coins back to Coinbase. I moved them back to MetaMask and transferred back to Coinbase. It was sent under “Matic Mainnet” in the MetaMask and the transaction was completed. But it has been 2 days and the fund hasn’t appeared in Coinbase. I contacted MetaMask but they said that they can’t reverse the transaction and I need to contact Coinbase. I contacted Coinbase but the support has been very unhelpful and they kept saying that the transfer has been deposited even though nothing appears in the activity…

I have read that sometimes the fund can get lost if you use unsupported network but i used the correct account ID and the network did appear in the MetaMask and the transaction shows that it’s completed so I am really really hoping that I can locate the missing fund recover it. I know it’s not a huge amount but it was still about US$1,000 and that’s a lot for me… If anyone has any idea of how to resolve this I will really appreciate it. Thank you so much in advance.

What does that mean? After 7 days and if it fails to complete the transaction will the fund go back to my Meta Mask?