Nextcloudpi docker image extremely slow upload

Hi folks

I am new to docker, and to nextcloud.
I’m running archlinux on my pi, and have just installed docker and NCP.
It works pretty well. However, uploads take 10 - 20 x the time they should.
I can xfer back and forth with samba and get wire speed.
Downloading from NCP works great.

Uploading is ridiculously bad.

Any suggestions for how to troubleshoot this would be great.

thanks

On the left, uploading to nextcloudpi inside docker, on the right, copying to the pi via samba. (But not into the docker environment).