Hardhat deployment script fails with an Error: Timed out waiting for proxy admin contract deployment to address

Make sure to read the recommendations in the error message. It timed out waiting for a transaction that hadn't been mined yet. You can rerun the script and it will resume waiting for the same transaction. Reference: https://forum.openzeppelin.com/t/cant-deploy-a-new-implementation-contract-or-a-new-proxy/27313