Can there be a git flow that allows branches to be merged staging/development but not to master?

My git flow is similar to the github flow- ephemeral feature branches that merge to and from master after code review and QA.

However there is one important difference- in order to QA, developers merge to staging. In most cases this merging happens in the CI- merge conflicts are rare.

There are (atleast) 3 issues:

1. In some cases, some PRs make it to staging but not to master (PRs get rejected). For now, developers deal with it by manually re-setting staging to master.
2. In master we do a “squash and merge” while in staging its the standard merge. No specific issue because of this right now but seems like it might break in the future.
3. Merge conflicts have to resolved twice- once when deploying to staging, and another time when merging to master.

Is there a way to achieve to have branches to have code deployed to staging but not to master and keep stanging and master somewhat in sync without manual intervention.

One idea that comes to mind:

The CI keeps track of which branches are in staging (but not in master)- say all open PRs that a developer has marked “ready for staging”. On every staging deploy, the staging branch is reset to master and these branches are merged. But I’m not sure how a CI would save this kind of “state”. Not to mention, this seems like a very complex flow.