I have a custom writing pad control on one tabbed page and it works fine with iOS.
But on Android, finger movements started horizontally will be captured by the TabbedPage. Only finger movements started with vertical movements can be captured and processed by my writing pad.
Thank you for taking the time to submit the bug. We tried to reproduce the issue you reported but were unable given the description. If you could please attach a reproduction to the bug by starting with a clean Xamarin.Forms project and adding just the code necessary to demonstrate the issue, we would very much appreciate it.
For your convenience, we have created some reproduction best practices viewable here: https://gist.github.com/jassmith/92405c300e54a01dcc6d
Xamarin Forms Team
Created attachment 17371 [details]
I just put a drawing pad on the Tabbedpage, and if you swipe vertically, the drawing pad catches the gesture and draws the line, if you swipe horizontally, Tabbedpage will start changing tabs.
Should be fixed in 2.3.4-pre1. Please note that you will need to opt in to this fix using the Platform Specific Feature documented here: