RDS MySQL upgrade takes forever due to 0% repeatly snapshot creation

I am upgrading RDS MySQL from 5.7.34 to 5.7.37 but it takes forever. The log says:

• February 28, 2022, 8:34:21 AM UTC - Backing up DB instance
• February 28, 2022, 8:31:06 AM UTC - Backing up DB instance
• February 28, 2022, 8:27:45 AM UTC - Backing up DB instance
• February 28, 2022, 8:24:16 AM UTC - Backing up DB instance
• February 28, 2022, 8:20:49 AM UTC - Backing up DB instance

It tried to create the new snapshot every 3-4 minutes before upgrading but every snapshot stuck at "Creating" "0%". Unfortunately, the DB cannot be deleted due to enabled delete protection. Therefore, it run upgrading forever :(

Please advice.

Thanks Account ID: 358204806461