The paid app and subscriptions are 2 different versions designed for different user groups. If you purchased the CamScanner license via Google Play, the app will be listed as "purchased" on Google Play and you can install it again freely. If it still doesn't work, pls report to us from the CS app--Me--Feedback. Thanks
Please accept our apologies for the inconvenience caused. Could you describe the issue you met in detail and report to us from CS app--Me-Feedback and attach some screenshots of the issue for analysis? We'll try our best to find the solution. Thanks
Please open the CS app on your phone--click the "camera" icon--click top right three dots icon--tap the bell icon (or swipe up to find "Sound") to turn on/off the sound.
However, in some android versions and device models, cutting off the sound is not supported for 3rd party applications.