Source locale changed when translating nested pages - with no translated sub-tree created

[vellip]

I don't know if this is actually a separate issue or not, but this always happens to me after I did what I described here.

I have a wagtail page with three models, that are nested within one another like so:

1. Group
2. Module
3. Screen

When in sync mode and I just created a module with a screen, it also created the aliases for it in synced languages. However, after I do what I describe in #792 and go ahead to delete the aliased module, then go back to the source language and hit "Translate this page" it actually creates a translated page for the module, none for the screen and when going back to the source screen, the locale now changed from whatever it was previously to the target language.

Reproduction Repository: https://github.com/vellip/wtl-repro (database is included, superuser is admin:admin)

How to reproduce:
https://github.com/wagtail/wagtail-localize/assets/16354712/8876f84c-1911-47fd-97a9-99db3b78b721

[zerolab]

@vellip what wagtail-localize version are you using?

[zerolab]

I believe this is what #773 describes as well. Was able to replicate