It may be fixable, but I'm missing too many things.
Do a version of the test I suggested, but change as follows. If it turns out to be easier, so be it.
You can "import as menu" your current menu. Select it in the current project, then Menu -> Save Menu as File and pay attention to where you save it.
Create the new project with a new name. Import as menu the menu you saved above. (It will be first play and the title remote will be set by default.)
Then add your timeline: File -> Adobe Dynamic Link -> Premiere Pro Sequence, find your project and select the sequence.
Do not add chapters, etc. Just add a link from the play all button to the timeline. Select the timeline and se the end action as "Return to last menu." Do not transcode.
See if it previews.