Wrong communication of gradients for periodic cases

[pcarruscag]

FYI
Introduced in #1009
Found by @TobiKattmann
Fixed in #1020

[TobiKattmann]

Thanks for incorporating that fix into your PR. I actually wanted to propose to put that commit into another PR… but you were faster to do so 🏃‍♂️ 💨
The relief after knowing the root caused me to deviate from the necessary follow-up.

[pcarruscag]

No prob, we can cherry pick all these fixes into a new PR if my one does not go through for the next release.