I’m pleased to say that I’ve found a solution that works. By enabling access to all Wnd Class, the CJK IME stuck in sandboxie issue has been resolved. I’m curious, though: was I the first to discover this solution? I’ve attached a screenshot below to show the necessary settings in Sandboxie-Plus. No additional settings are required.
Imperfect workaround: Right click the new sandbox running Tencent Meeting and enter Sandbox Settings. Go to Resource Access > Window Access. Click Add to add a new item providing an asterisk (*) as its name. Apply this modification. Open Tencent Meeting to test screen sharing. In addition, if any bluetooth device is used, append “OpenBluetooth=y” under the section of [tencentmeeting], the name of the sandbox holding Tencent Meeting, in the configuration file which can be edited via Configure > Edit Configuration. Without this enabled in my computer, screen sharing of Tencent Meeting also fails. In my testing, it can work at most times with those modifications but still occasionally fails.