As stated above display scaling does crazy things with this plugin.
I changed back to 100% and interface is ok again.
Change it back to 150% (I have a 4K monitor) while keeping Paint.net open and interface stays ok.
Close Paint.net and reopoen > Interface is broken again.
Newest version of paint.net screws up the layout of this plugin.
Anyone else also has this problem?
It's only possible to grab and drag the upper left marker
The other fall out of the interface.
Edit : reinstalled, but issue remains