I had the same issue, and posted to the ubuntu forum.
The solution for me was to go to Settings->Configure Konqueror->Performance and uncheck the box "Always try to have one preloaded instance".
After logging out and back in to get kdeinit5 reloaded, I can launch Konqueror multiple times per session, and there is no longer a zombie process.
I had the same issue, and posted to the ubuntu forum. >Performance and uncheck the box "Always try to have one preloaded instance".
The solution for me was to go to Settings->Configure Konqueror-
After logging out and back in to get kdeinit5 reloaded, I can launch Konqueror multiple times per session, and there is no longer a zombie process.
ron