Could you please check if there is an update available for Acrobat Reader?
Launch Play Store on your device>tap My apps & games
Also, try rebooting the device and see if that resolve the issue with scrolling.
Have you tried switching between these scrolling modes- Single Page/Continuous?
Please refer to this link for more info: Acrobat Reader Help for Android: Set Viewer options
Let me know how it goes.
on my OnePlus 3T I have the same problem. Scrolling is very laggy in continuous reading mode. I noticed it after updating to Android 7.1.1. Clearing data, reinstall didn't help.