@Linicks That error simply means your account could not be found on the testnet blockchain at the time. If it were you would have seen an account balance. Even though the funding transaction was successful, it seems like it was not added to a block that was written to the blockchain. I would run the curl command again and check the explorer after a while.
https://explorer.nightly.jormungandr-testnet.iohkdev.io
Also an ambassador was asking for your Telegram account handle. Did you give it to him? Because the best way to resolve your issue is to dig through the Stake Pool Best Practices Tg channel.
Here’s the post to provide your TG handle