Creation of empty projects upon deleting an activity that contains activities

Hello,
I am encountering a problem with my ProjeQtOr, when i delete certain activities it creates empty projects.
Currently working with ProjeQtOr V8.5.4 

In the project structure i have 3 levels of projects and 3 levels of activities. Upon deleting any level of project that contains other levels of projects and activites i am not encountering any issue.
However upon deleting any level of activities that contains lower level of activities there is a big number of empty project that are automaticly created.

For example i have the following structure : 
Project lvl1 "ZZ_PEPS_TEST"
   Project lvl2 "TMA part 2" 
      Activity lvl1 "tma lot 2"
         Activity lvl2 "lot 1 act1, act2, ..."
 

When i try to delete the Activity lvl1 "tma lot2" i have the following confirmation pop-up that appears , warning me that the 4 activities attached will also be deleted


After pressing the OK button, the page starts loading for a few minutes. After that the following empty projects are created : 
 

From what i understand every child activity under the parent activity that has been deleted adds 50 empty projects. In this case deleting the parent activity that had 4 children activities created 200 empty projects (if i add one child activity it goes up to 250).

Can you please help me or provide me with any information that could prevent this from happening ?

Thanks,
Thomas