To be able to copy files over from iPad to Samba-shares the enhanced compatibility with Apple SMB clients and interoperability with Netatalk 3 AFP fileserver must be enabled.

Vfs-module is typically missing if you see in tshark messages like:

310 Create Response, Error: STATUS_OBJECT_NAME_INVALID;Read Response, Error: STATUS_OBJECT_NAME_INVALID;Close Response, Error: STATUS_OBJECT_NAME_INVALID

To get this fixed add to the [global] section in /etc/samba/smb.conf the following command:

vfs objects = fruit streams_xattr

The package samba-vfs-modules must be installed prior restarting the smb service.
Check if the package is installed with commands like:

ubuntu: dpkg -l samba-vfs-modules
RHEL. : rpm -qa | grep  samba-vfs-modules
etc.

a positive output looks similar to:
root@raspi24:/home/ugu5ma# dpkg -l samba-vfs-modules

Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name                    Version                   
+++-=======================-=========================
ii  samba-vfs-modules:arm64 2:4.15.13+dfsg-0ubuntu1.5         

If the package is missing add it with:

ubuntu: apt install samba-vfs-modules
RHEL. : yum install samba-vfs-modules
etc.

Restart Samba:

systemctl restart smbd

Done!