Lightsail deployment "Took too long"

I performed Lightsail deployment following this guide: https://aws.amazon.com/tutorials/serve-a-flask-app/

When deploying my container, I keep getting the "Took too long" message in the longs and all deployments fail. This is not helpful and I'm not sure what went wrong.

What I've tried:

• Increasing capacity up to Medium x3
• Adjusted Health check timeout seconds to 60
• Adjusted Health check interval seconds to 120

After deployment failure, I wait a while and I see the flask app is running in the logs. However this is after deployment "failed".

When I try to access via public domain, it says 503 Service Temporarily Unavailable.

What do I do?