Jose Manuel,
I tried with the samba 4.11.7 package from your PPA and the bug still occurs with "Files"
Andreas,
I have no shell access on the NAS so I am unable to check smbstatus. However I can confirm you that it always uses SMB1. This NAS does not support SMB2/3.
I could capture SMB traffic with Wireshark. Would it help you ?
Jose Manuel,
I tried with the samba 4.11.7 package from your PPA and the bug still occurs with "Files"
Andreas,
I have no shell access on the NAS so I am unable to check smbstatus. However I can confirm you that it always uses SMB1. This NAS does not support SMB2/3.
I could capture SMB traffic with Wireshark. Would it help you ?