and I confirmed it by testing many times. So here I report it to Zotero Dev Team.
Step by step:
1. Unchecked some checkbox settings in my plugin preferences pane. (for example the checkbox for enabling toolbar button)
2. Again install my plugin.
3. Now, strange behavior happens: the unchecked checkboxes in step 1 will be checked automatically by Zotero. Here I am very sure there is no any codes doing this in my plugin. (My plugin has been running well for many years)
4. Again do steps 1-3, this behavior can be reproduced. (even after restarting Zotero)
This strange behavior does not happen in Zotero < v7.0.22, and Zotero 8 Dev.
I can't figure it out. Hope the Zotero Dev Team can share some opinions about this.