plasma version 5.7.2
frameworks version 5.24.0
qt version 5.7.0
kernel 4.4.0-21
cpu intel core i7-4790T  - intel hd graphics 

i configured a vertical panel on the left side an "pinned" some applications (show a launcher when application is not running) 

especially the chrome launcher icon (probably just my most used app) is often hidden..




Reproducible: Always

Steps to Reproduce:
1.start chrome (or any other app) from the panel 
2.close chrome


Actual Results:  
the chrome launcher that was used to start chrome is gone

Expected Results:  
the chrome launcher should still be there

starting chrome from the startmenu (button>internet>chrome) displays the running chrome app in the taskmanager properly..  
the context menu tells me that the configuration to show a launcher when the app is not running did NOT change...  it is still set to show a launcher!

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i just configured the taskmanager to sort applications manually and only allow 1 row of icons.. 
i will report here if the problem remains with this configuration