I noticed a bug on two servers - one running Linux, one running Windows, so possibly affects all environments.

When there is a spawn protected area, non-op users are able to open doors but cannot walk through them. It seems as though the client has updated with the new model for the open door, then when they try to walk through the server believes that they should not be allowed? This is just my guess. It results in what seems like rubber banding while trying to get through the door.

Making the user an op or removing the spawn protected area resolves the issue.