SUMMARY

Google Chrome's default configuration is to use client side decorations - the browser draws a combined window title bar and tab bar. This can be disabled by setting "Use system title bar and border" under Settings->Appearance to restore kwin drawn decorations.

With the default setup (CSD), when Google Chrome is started, it is always started showing in all activities - as can be seen by opening the window operation menu for the Google Chrome window - and the user has to manually set it to the correct activity after opening. 

The default (and expected behavior) of application is to start showing only in the activity that was current when they were started.

STEPS TO REPRODUCE
1. Install Google Chrome from Google's website
2. Make sure no old configuration exists by rm -rf ~/.config/google-chrome
3. Make sure multiple activities are active
4. Start Google Chrome

OBSERVED RESULT
Google Chrome is showing in all activities

EXPECTED RESULT
Google Chrome should show only in the activity that was current when it was started.


SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 
KDE Plasma Version: 5.18.80
KDE Frameworks Version: 5.67.0
Qt Version: 5.12.5

ADDITIONAL INFORMATION
The expected behavior can be enabled by configuring Google Chrome to "Use system title bar and border".