Samba save file access from Linux

Hello All

I am running a Pi4 with Buster.

On the Pi itself, I can read and write files in a folder. I then shared the folder via samba. I can read the same files from a Linux client but if I change anything and try to save, I get the following error:

Could not rename partial file smb://raspberrypi.local/OUR_STUFF/Rick Stuff/Documents/filename.part.
Please check permissions.

The save operation leaves a filename.part on the server. I have to discard the save. Odd thing is, if I use 'save as' and rename the file, it writes fine.

The same thing happens if I create a file in the server from the Linux client.

Windows 11 client reads and writes with no issues.

The whole directory tree reads 0777 when on the server.

This appears to be a Linux permissions issue but I have no idea where; on the server or on the Linux client.

Here is my samba.conf:

[OUR_STUFF]
comment = shared folder
path = /home/pi/OUR_STUFF
browseable = yes
writeable = yes
only guest = no
create mask = 0777
directory mask = 0777
public = yes
guest ok = yes
force user = pi
force group = pi

Any ideas?