Intermittent failures reading from remote repository

The command "git ls-remote --tags --heads git@bitbucket.org:${username}/${repo}.git" is failing quite often as part of a Jenkins job. I ran the command manually four times back-to-back on the AWS EC2 instance and it failed twice and succeeded twice. When successful, it returns the information in less that 2 seconds. When it fails, it trys for 5-6 minutes, then returns

ssh: connect to host bitbucket.org port 22: Network is unreachable
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

This behavior seems to start yesterday and is worse today.