SUMMARY
I do not know if this is a bug, but other KDE users on forum.kde.org have expressed that this is not normal, but could not provide a solution.
Can you help me fix this, please?

STEPS TO REPRODUCE
I have 4 activities with a dolphin instance open in some of them.
There is a folder or link to a folder on my desktop. Click it to open the folder

OBSERVED RESULT
The folder opens as a new tab in the first of the next activities that has a dolphin instance, but never in the activity where I clicked even if there is an open dolphin.

EXPECTED RESULT
Tab should open in dolphin of the same activity where I clicked on the folder. If there is no open dolphin, it should start a dolphin instance within the activity where I clicked on the folder.

SOFTWARE/OS VERSIONS
Manjaro stable (I installed Manjaro KDE last year and this never worked)
Dolphin 19.12.0, 19.12.1
KDE Plasma Version: 5.17.4, 5.17.5
KDE Frameworks Version: 5.65.0, 5.66.0
Qt Version: 5.14.0 

ADDITIONAL INFORMATION
Starting with an empty desktop session did not help. I also tried switching back to "use common properties for all folders" in dolphin settings, but it did not help either. I am not using virtual desktops (there is only 1).