Safari's UI and Preferences not working.

So yesterday I updated Safari from 14.0.2 to 14.0.3 along with Mojave system update.

After updating, my Safari is acting weird.

I adjusted the tool bar icons, tweaked some stuffs in Preferences. (Background image for safari starting page, save browsing history for how long, open new window with what webpage, etc.)

And after I quit Safari app and re-open it, the whole preference settings are gone,

as like it's just newly installed Safari.

And again I re-tweak Preferences settings, re-open it, gone.

Weird thing is that everything that has to do with iCloud seems works fine. (iCloud Tabs, Keychain, Bookmarks, even browsing history all worked fine.)

Only the 'UI part' and Preferences settings of Safari always 'reverted' to default status.

I've tried disable all extensions,

removed ~/Library/cache

cleared browsing history

cleared browsing cache

reboot Mac in Safe mode

reset NVRAM

removed any .plist in ~/Library associated to Safari.

Nothing fixes it.

This happens right after I updated to 14.0.3,

and I didn't install/remove any app or Safari extensions after updated.

So I'm supposing this has something to do with the update itself.

I'm currently running Mojave 10.14.6 on mid-2015 MacBook Pro Retina 2.5G intel Core i7.

Please help, thanks.