FreeFileSync is very slow from Fritzbox to Fritzbox

[elchico]

Hey everybody,

I am using a Windows 10 Laptop with a network drive, connected to my home FritzBox. I have another network drive connected to the FritzBox of my parents. I want to use FreeFileSync, to synchronize a folder on the network drive of my FritzBox with a folder on the network drive of the FritzBox of my parents.

Issue: If I go to the network drive of my parents, I browse to the NAS of the Fritzbox and I can upload files rapidly (about 1.6 MB/s). This was tested like 10 min ago. If I want to do that with FreeFileSync, last week it was about the same speed. Now, it is about 1-100 KB/s.

Does anybody know something about this issue? Was it reported already?

Thanks.
Michi

[elchico]

Attached you can find the settings + an overview of the sync.

Michi