Microsoft announced new Mobile preview build 14342.1001. Currently, only fast ring insiders get this new mobile build. The new mobile preview build also comes with bugs. Check known issues list with new build 14342 below.

Known issues for Mobile Build 14342.1001:

We are investigating data issues with some Dual-SIM devices where cellular data doesn’t work correctly with a second SIM. Several issues relating to cellular data with Dual-SIM devices have been reported by Insiders with the last two Mobile builds and we’re investigating these reports.

Feedback Hub is not localized and the UI will be in English (U.S.) only, even with language packs installed.
We have reduced the number of instances where boxes are seen when entering emoji. You may still see them in some text fields – we’re working on it!

The Settings app may crash when you are re-arranging Quick Actions under Settings > System > Notification & actions. If it does, it could result in one of the Quick Action spots disappearing. If you see this happen, please refrain from changing your Quick Action settings on this build. If you have been impacted by this issue, only a hard reset will revert your Quick Action settings back to default.

Check here what’s New in Mobile Build 14342.
Check here what is Fixed in Mobile Build 14342.