Button opens modal with autocloseable modifier. After click modal shows a one moment. It's happens because modal catches 'click' event. The 'click' event is a program event after 'touchend'.
I can reproduce in iOS (bem-core#v4), AndroidBrowser (bem-core#v4, bem-core#v3), Chrome for Android (bem-core#v4, bem-core#v3), Chromium on Windows 10 with touchscreen (bem-core#v4, bem-core#v3).
@vsesh