Reaper behaving superslow

[reapero]

I have a project with no fx at all, just some vo recordings..about 150 tracks. And regular operations like clicking on an empty area in the arrange view takes like half a second for the cursor to get in place. Also hiting play...everything is super laggy.

Happened before in other sessions but now i realized it has nothing to see with resources. If i look at the task manager the Reaper process is taking about 5% CPU and 250MBs of memory.

I am runnig the following defer scripts at startup:

Lokasenna Track selection follows item selection
mpl_InteractiveToolbar
BFO&LKC Folder items


Windows10, latest Reaper version.

Any idea?