We have an application with several top level tabs. In the middle of several other changes, we decided to change the order of these tabs. We then published the changed app, and updated another customer zone to the new version. The new tab order was not reflected in the second customer zone after the update finished. Afterwards, I was able to reproduce this error where the only change was the order of the Application's tabs.
I'll take a look.
Fixes in 3.8.0 release