deployment tells me it's failed but actually succeeds

I continually get this error

error: cannot lock ref 'refs/remotes/origin/master': when I push to Bitbucket and Forge attempts a deployment.

I also get an email from Forge to tell me the deployment has failed but the changes do actually deploy.

Has anyone else experienced this?

Happens on every new server/site I spin up these days.

No big deal ultimately, just a slight inconvenience having to dismiss the 'failure' notices.

What's the best way to resolve?