Extremly poor SMB transfer performance, but transfers to/from Nextcloud, Seafile, Immich, etc are fast.

Hi,

I have a server setup with a NVMe only pool which I want to use to transfer files over to without the bottleneck of having to calculate parity during large transfers (20-30GB video files). The server has full gig up/down, and I regularly get 80-105MB/s down on the server.

When I'm connecting to my server remotely via wireguard, I can only download/upload to my NVMe share at around 2-3MB/s. But when, again connected through the same VPN, if I try to upload the same files to Nextcloud, Immich, or Seafile, I get my full upload speeds roughly 50-60MB/s. This is regardless of client. I've tried windows, mac, linux, and android. Same speeds on SMB no matter what.

Can someone help me out with anything I might be missing? I haven't 'fine-tuned' anything in my SMB settings, but I'm open to try anything at this point. I've been having this issue for months, since I started my server.