The scene was recently added in the time skip phase.
When you enter the time skip act „Preg“ with Tsubaki pregnant, her class advanced to Blademaster, you have her katana Setsuna, and the bakery is build, an icon will appear between the bakery and the barracks of the vanguard which will start an event line in multiple steps in the „Preg“ and „Birth“ acts.
Yes. If there is still a problem with unlocking Tsubaki's scene than I can check what you're missing.
However, I can't search for vague issues for which I don't know where or for what to look. The story is already at the current end for you in the time skip, which is still a work in progress and has a lot of unfinished acts. So unless you have specific events that don't trigger, I'm not sure what help I could give you.
