I setup Jenkins to use ssh with Github.

Add public key to deploy key on GitHub
Add private key to jenkins project.  Record id for Jenkinsfile
Get host id: ssh-keyscan github-stg.corp.zynga.com
Copy the key for ecdsa-sha2-nistp256. 
Add to Jenkins manage -> security -> Git Host Key Verification Configuration -> Manually provided keys

I was able to successfully build.  I am using pipeline builds. 
I then switched it back to https and I get a connection error.  The console shows that the connection is fine. 

But the build gives an error:
20:00:42 Started by user
Matt Peterson
20:00:42 Running as
Matt Peterson
20:02:53 hudson.plugins.git.GitException: Command "git fetch --tags --force --progress --prune – origin +refs/heads/main:refs/remotes/origin/main" returned status code 128:20:02:53 stdout: 20:02:53 stderr: fatal: unable to access '
https://github-stg.corp.zynga.com/mapeterson/deploykey_test.git/
': Failed to connect to github-stg.corp.zynga.com port 443 after 131052 ms: Couldn't connect to server*20:02:53* 20:02:53 at PluginClassLoader for git-client//org.jenkinsci.plugins.gitclient.CliGitAPIImpl.launchCommandIn(CliGitAPIImpl.java:2848)20:02:53 at PluginClassLoader for git-client//org.jenkinsci.plugins.gitclient.CliGitAPIImpl.launchCommandWithCredentials(CliGitAPIImpl.java:2184)20:02:53 at PluginClassLoader for git-client//org.jenkinsci.plugins.gitclient.CliGitAPIImpl$1.execute(CliGitAPIImpl.java:635)20:02:53 at PluginClassLoader for git//jenkins.plugins.git.GitSCMFileSystem$BuilderImpl.build(GitSCMFileSystem.java:408)20:02:53 Caused: java.io.IOException*20:02:53* at PluginClassLoader for git//jenkins.plugins.git.GitSCMFileSystem$BuilderImpl.build(GitSCMFileSystem.java:413)20:02:53 at PluginClassLoader for scm-api//jenkins.scm.api.SCMFileSystem.of(SCMFileSystem.java:219)20:02:53 at PluginClassLoader for workflow-cps//org.jenkinsci.plugins.workflow.cps.CpsScmFlowDefinition.create(CpsScmFlowDefinition.java:126)20:02:53 at PluginClassLoader for workflow-cps//org.jenkinsci.plugins.workflow.cps.CpsScmFlowDefinition.create(CpsScmFlowDefinition.java:73)20:02:53 at PluginClassLoader for workflow-job//org.jenkinsci.plugins.workflow.job.WorkflowRun.run(WorkflowRun.java:311)20:02:53 at hudson.model.ResourceController.execute(ResourceController.java:101)20:02:53 at hudson.model.Executor.run(Executor.java:445)20:02:53 [Checks API] No suitable checks publisher found.20:02:54 Finished: FAILURE