Issues with arc in curved surface

I use the plugin ToolsOnSurface but have issues when creating arcs.

When creating a arc inside group (right), the tool goes grazy and I cant create the arc like I want.
If I create the same arc outside the group (left), then it works perfect.

How can I solve or get around this?

Select and cut the arcs you create outside and place them inside the group with Paste in Place.

Great thank you!