Firefox iOS erases all private tabs on reopen

[SpyglassRealms]

Steps to reproduce

Open Firefox iOS. Swipe to private browsing mode. Open any number of private tabs. Close Firefox (as in: fully close session by entering app switcher and swiping up so that the app is no longer running in the background). Reopen Firefox.

Expected behavior

All tabs in private browsing mode should stay as they were: keeping their respective histories, tab order, etc.

Actual behavior

All tabs in private browsing mode are completely and irretrievably gone.

Device & build information

• Device: iPhone SE (generation 3) running iOS 17.5.1
• Build version: 127.0
• First seen version: 127.0 (This has happened after a previous update as well, but I cannot remember which one.)

  Notes

  Enhanced Tracking Protection is on and set to Strict. Inactive Tabs are enabled.

┆Issue is synchronized with this Jira Task

[ghost]

Thank you for reporting this issue, but there's already a discussion about it here: #20073.