Context menu pop-ups easily with short keypresses when changing focus on Split vew between QWidgets on TabWidget

Preconditions:

TabWidget includes Tab with many text input widgets: QTextEdit (top of the screen), QPlainTextEdit, QSpinBox, QLineEdit (bottom of the screen).
View is on portrait orientation.

Test steps:
1. Tap QLineEdit on bottom of the screen
--> split view is opened to portrait mode with qwerty virtual keyboard.
2. Change focus to QSpinBox (above the QLineEdit).

Expected result:
QSpinBox is focused on split view. Alphanumeric virtual keyboard is open on number mode.

Actual result:
Context menu pop-ups - even if the short keypress was pressed.
Error can be reproduced very easily when changing focus between QLineEdit, QSpinBox, QTextEdit.