Konsole disappears in activities after reboot

The following needs to be confirmed. It has happened several times already:

When stopping a KDE activity where a konsole is open, we can reactivate the activity latter and the konsole will still be there, with its tabs and all.

However, after a full reboot, the konsole disappears from some activities.

I still need to precisely observe what's happening and when, but sometimes I activate some activities and the konsole is not where it's supposed to be.