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UPDATE: To correct the bug description: After a reboot @ the login
screen, touchscreen works. But after entering my password and log in to
the desktop, touchscreen stops working (no matter whether it's the
'Ubuntu' or 'Ubuntu on Wayland' session).
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UPDATE: I tried switching to 'Ubuntu on Wayland' but touchscreen still
does not work after login.
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https://bugs.launchpad.net/bugs/1909944
Title:
Dell XPS 13 9333 Synaptics touch screen