Hi there,
We have looked around your issue and it seems that it's a "normal" behavior for Acymailing to interact with Hikashop in this way.
Actually, the automatic adding of recent product doesn't not look for recent variant since these variants are attached to a main product and it may disturb some users.
You can imagine that for someone selling shoes, adding each size of a specific shoe isn't really interesting...
Anyway, we'll think about that to determine if we can do something to simplify the process and make everybody happy, for now I think you can solve your problem by giving to your main product the variant's price you want to be displayed in the newsletter.
If this solution isn't good for you, you can still choose manually the variant and add it to the newsletter.
I hope these solution will help you
.