ls_rbls • Adobe Community Professional, Dec 06, 2020
Please make sure that you set the Acrobat Reader mobile app as the default app to view and handle PDFs in yourmobile device.
You can do so by tapping and long-pressing on the Acrobat Reader icon.
Then select "App info" from the context menu that will pop up next.
In the next screen you'll be presented with a few options. Scroll or swipe down until you see "Set as default". Tap on it to set your app as the default PDF handler.