File permissions over Linux - Linux share using samba

[Colin Law]

I am using Samba running on Pi OS (Buster) to share folders to Ubuntu
and Windows.
In the Pi /etc/samba/smb.conf I have

[usbhdd]
  comment = USB Disc Drive
  path = /media/usbhdd
  browsable = yes
  read only = no
  create mask = 775
  guest ok = no

In Ubuntu I am mounting it using

mount -t cifs -o
credentials=/path/to/.credentials,user,rw,uid=1000,gid=1000
//servername.local/usbhdd /media/server_usbhdd

Everything works fine, except for the fact that, viewed from ubuntu,
all the files have permissions 0755 whereas on the pi some of them
have, for example 0644.
If I add vers=1.0 at the start of the options string then the
permissions are correct on Ubuntu, but I quite correctly get a warning
saying I should not be using an old version.
I have googled and experimented but don't fully understand the
complexity of the options in samba so any help with this would be much
appreciated.

Colin Law