Merging is blocked - Missing successful active Preview deployment

Hi, this has happened to me again several times. Usually with a user pushing to a fork. I think it may be relevant by having an old “master” branch.

This particular PR is also having old base branch - but Github is showing Merging is blocked Missing successful active Preview deployment. and nothing about the branch. Could it be some Github bug?

https://github.com/zbycz/osmapp/pull/1110

I will leave to PR open for some time for possible investigation.

//edit somebody else is having the same issue