Unified Inbox selection not remembered

Checklist

• I have used the search function to see if someone else has already submitted the same bug report.
• I will describe the problem with as much detail as possible.

App

Thunderbird for Android

App version

10.0

Where did you get the app from?

F-Droid

Android version

Android 15

Device model

Nothing Phone 1

Steps to reproduce

There are two problems here but I believe they stem from the same underlying issue, that is, that the default view for each account appears to be its own Inbox.

Repro 1

• Install App
• Configure at least 2 email accounts
• Click on the hamburger menu at the top left
• Select "Unified Inbox"
• Click on the "create new email icon" at the bottom right
• At the top left, next to "Compose", click on the "changed my mind" (back) arrow
• Notice you land in your account's Inbox, not in the Unified Inbox where you came from.

Repro 2

• Install App
• Configure at least 2 email accounts
• Click on the hamburger menu at the top left
• Select "Unified Inbox"
• Click on the hamburger menu again
• Click on the account name at the top to switch to another account (imagine you just wanted to double check the email address of that account or its folder structure)
• Observe that you immediately land on the individual account's Inbox, rather than staying in Unified Inbox that you have previously selected.

Expected behavior

For Issue 1, if the user comes from Unified Inbox and cancels a draft email, the back arrow should take the user back to the Unified Inbox, where they came from, not to a completely different folder.

For Issue 2, just because the user switches accounts, to check for the account's email address or a particular folder, if Unified Inbox was selected before, the selection should be retained, unless the user explicitly selects another folder.

Actual behavior

Whenever a draft email is cancelled, or a switch between accounts is made, the selection resets to the given account's own Inbox.

Logs

Don't think logs will be of any use here, but happy to provide them if needed.

Reproduce both reported flows in Thunderbird for Android with at least two configured accounts, focusing on Unified Inbox selection during draft cancellation and account switching. Trace the navigation state around the Compose back arrow and account switch; done means the Unified Inbox remains selected unless the user explicitly chooses another folder.