After my investigation, it is said that the root cause could be a DNS resolution failure error in most cases.

So you can use dig command line to find out more details. For example, by using the command, dig {URL}, you are able to see if the URL resolves to IP address properly.

You can find more information for dig command from https://blog.ilearnaws.com2020/05/18/dig-command/

In addition, if you setup a private hosted zone in the Amazon Route 53 and the lambda is in a VPC, you may need to associate the VPC which the Lambda resides in with that private hosted zone. Then the Lambda should be able to connect to the host.