respeccing the passive tree sometimes doesn't work as displayed

When I respec the passive tree, sometimes I get a mix of the old and newly chosen passive tree, instead of the newly chosen passive tree it displayed.
This is a really annoying bug, because it means additional respec costs and I need to look at every node: which ones were changed and which one are still remains of the old passive tree.

I have the impression that program does not replace the entire old passive tree with the new one based on my new choices, but instead tries to rebuild it out of the old one. The issue seems to mainly occur when I delete "old nodes that were required for pathing" and add "new nodes to fulfill the pathing requirements for the new tree in a different way". In the rebuilding process the "old required notes for pathing" seem not to get deleted, because the program assumes they will be still neccessary in the new passive tree. The result is a mix of the old and the new intended passive tree.

A different issue is that it sometimes doesn't let me convert normal passive tree points into weapon set passive tree points, if I would run out of skill points (the program doesn't account for the fact that I "get a skill point back" when converting a normal skill point into a weapon set skill point).