Regen is a four independent tracks looper.
It accepts stereo input and supports 4 stereo outputs.
In GP (Windows 10), it is loaded as a mono in/out plugin and appears twice in the plugins windows.
It is as if GP sees 2 mono plugin instead of a stereo one.
Ouch! GP is great and community members are valuable
I spent a lot of time reading the user manual and I missed that one.
But however, by looking at the page concerned, I found that the link above is inactive: