Probably using problematic RPC since your TX didn't get through and doesn't seem to reflect on the blockchain.
Have you tried other RPC?
but since it's testnet and the fee is volatile, I think you need to increase gas fee just in case.
i dont think it's just about rpc. i suspect it's meta mask. when i try to make tx on main net i face same difficulties.
tx failed
am using 2 PCs same issue with both.
am using the chrome extension
might be your internet connection honestly if that's the case, maybe they blocked the RPC as other have stated.
metamask is just an UI that help interact with the RPC, the data fetched ultimately come from the RPC.