Microsoft has a long list of what bug have been fixed, and what is broken, with the new Windows 10 Mobile preview build 14283 that was released to Insiders on the Fast ring.

Here's what's fixed in this build, according to Windows Insider head Gabriel Aul:

  • We have addressed an issue where the background behind the All apps list would not have an overlay (causing it to appear too bright or too dark, depending on your background) if you went back to All apps list after launching an app.
  • We fixed an issue causing the title of a song in volume control to flicker a few times when you pressed play or changed tracks after a pause.
  • We fixed an issue some users were experiencing with Build 14267 where your device could hang while typing and reboot.
  • We made some more improvements to the Live tile refresh logic. First, if there are pending notifications for several Live tiles, we will now update them in one quick sweep across the Start screen rather than one at a time. Second, if a Live tile has both badge and content updates, they will now appear at the same time. Finally, apps will now launch faster from the Start screen if there are incoming Live tile updates at the same time.
  • We fixed an issue where Live tiles for certain apps (such as the Weather app) would sometimes unexpectedly be cleared of active notifications.
  • We fixed an issue in which the Start screen background would appear to stutter behind the tiles when scrolling up and down the Start screen on some devices such as the Lumia 950.
  • We fixed an issue where the keyboard would sometimes pop up when swiping over to the All apps list.
  • We fixed an issue where icons for certain apps would appear too tiny on Live folders on the Start screen if your phone was set to 350% DPI.
  • We fixed an issue where "More notifications" message in Action Center was not properly formatted.
  • We fixed an issue where for certain languages, pressing "@" button could result the contents of the clipboard being pasted.
  • We fixed an issue where notifications using custom sounds would be silent if the underlying audio file had been deleted. Now, if that file is not present, it will play the default notification sound.
  • Connected to wireless displays should now work by going to Action Center and expanding Quick actions and choosing "Connect".

There are also a few known issues in this build:

  • We have updated the Bluetooth AVRCP profile on mobile to version 1.5. Some cars only tell Windows what they support and vice versa during the initial pairing ceremony. In order for this update to take full effect, you need to delete your existing Bluetooth pairing with your car and then re-pair. After doing so, if you notice any issues using media playback controls or missing artist or track info, please file a new feedback item including your car's make, model, and year.
  • If you have a Microsoft Band 1 or 2 paired to your phone, it will no longer sync after updating to this build due to a system API failure that occurs after the update. If you want to get your Band syncing with your phone again – you can temporarily change the language of your phone as a short term workaround until we release a fix. Additionally, you can also choose to reset your phone to get out of this state – however you may experience this update issue again with the next build until we fix this issue. This issue may also impact Skype video and audio calls.
  • We are investigating an issue where the Gadgets app is not able to detect the Microsoft Display Dock on phones running Windows 10 Mobile Insider Preview builds, and thus cannot update the firmware version. If you have a dock which has already been updated to version 4 then this will not affect you. If you have a dock that has not been updated, then you may experience some minor issues with USB-C stability.
  • Connectivity to older Wi-Fi networks using the WEP encryption security method may be broken. WEP is an insecure method for protecting your Wi-Fi connection but a small percentage of Windows users still use it. A workaround would be to configure your wireless routers to use WPA or WPA2 or wait for the next Insider flight when this is fixed.

As always with new preview builds, there are also likely bugs that have not yet been discovered by Microsoft