Hi,
Thank you for coming Microsoft Q&A.
I have not found any related issue or known issue on 20270 system version.
If issue occur once installed update package, try to uninstall it to check if all issue disappear. If the issue disappeared, try to feedback it through Windows 10 Build-in application "Feedback Hub".
As I noticed you are using insider system version for dev channel, I would recommend to post your thread in Windows Insider Program. You could get more information from that special insider website.
Bests,
============================================
If the Answer is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.