Check the source of holster.
Make sure that your phone holster is made by Samsung. If in doubt, you can take it to the service center for testing.
Remove the holster again
Try taking apart the holster again, sometimes it's just a simple installation problem.
Check third-party software
Check whether the mobile phone has recently downloaded new third-party software, which may be caused by incompatibility between the software and the mobile phone. You can try to uninstall this software in Settings-General-Application Manager-Download.
Restore factory settings
If the above steps can't solve the problem, it is recommended that you back up your mobile phone data and then restore the factory settings.
Maintenance service center
If the problem still exists, it may be a problem with the mobile phone system software. I suggest you take the purchase invoice and maintenance card and send your mobile phone to the nearest Samsung service center for testing. The address of the service center can be found here:.