Hi Gvolt, many thanks for your kindness. Please see my answer as followed:
What specific waveshare touchscreen do you have?
My touchscreen is the official 7’’ touch screen.
How is it connected and what did you do software wise to install it?
I actually installed the touch plugin first, and then wired the SDA and SCL cables.
Did you do anything to change the display and/or touch orientation? If so, please describe the changes that have been made.
Yes, I reversed the display in the touch plugin settings, cause with the official 7’’ screen case, Volumio displayed up side down, that’s why I did a reserve for the display.
Did you have an older version of the touch display plugin (<1.1.1) installed previously?
No, I installed the plugin for the first time on August 18. But it took pretty long time to install, and waited many time at the point of 70%, but finally it was installed successfully after around 20 minutes.
Does the touch functionality completely fail or “only” in the area that has been touched once?
I tried couple of times to reboot the PI, and every time when it started, the “only” area can be touchable, but only once, I can’t even unfold the menu.
Do you see any error messages on the UI or in the logs? If so, please post them.
No, I don’t see error, it works very good except the touch screen.