Not sure, you can run a coordinator yourself. You don't need to register any domain name first, you can run the .onion server from your laptop. This guide is (mostly) accurate, you can start a coordinator with only ~3 prompts to your LLM for help: https://github.com/kravens/bitcoin-educational-content/blob/dev/tutorials/privacy/coinjoin-coordinator/en.md

Ok thanks, but I did not find any coordinator URI for signet. Are there any?

The problem of the 4,294,966,286 block height was just fixed in this PR: 

I can't vouch for the stability of Testnet 4, there is already progress on launching Testnet5: 

If it stays stuck for >30 minutes, try closing and restarting your client, or switching to Signet. Thanks for testing Wasabi!

Coinjoins

Playing with Wasabi in Testnet4

The problem of the 4,294,966,286 block height was just fixed in this PR: https://github.com/WalletWasabi/WalletWasabi/pull/14902

I can't vouch for the stability of Testnet 4, there is already progress on launching Testnet5: https://github.com/bitcoin/bips/pull/2196

If it stays stuck for >30 minutes, try closing and restarting your client, or switching to Signet. Thanks for testing Wasabi!