I found out, that I can't restrict a coupon to one product. It was also not possible to manually add product to an order. Why? Because the product search field stopped working.
With a copy of my shop, I deactivated one plug in after one. After deactivating FPD - the field started working again.
The fields look different with active FPD.
Does anyone else have this issue?
I reported it already to radykal, only want to share.
See the pictures:
First picture - with active FPD - the search field is blocked.
The FPD PlugIn is deactivated - the search field works again.