User blog comment:MisterWoodhouse/The first migrations to the Unified Community Platform/@comment-26244866-20201001083601/@comment-26244866-20201001085349

Migrated communities seem to lack the top bar things when using "View Full Site"

Here is a comparison between a non-migrated (Community Central) and migrated (Spyro Wiki) wiki:

And as far as I recall, this problem used to happen (before the wiki migration) at some point in the past as well (for all wikis) but it was fixed.