Setup:

AX55 with USB network Hard drive connected for network use (Seagate firecuda 2TB in NTFS format)

with username and password security option

Able to access it in windows

Family uses ipad / mac/ iphones

Able to connect to network drive using FILES app (connect to server)

No problem in reading

No problem with non picture saving to network drive. (PDF. MS word docx)

ISSUE: when selecting photos and save to network drive. It state cannot save error.

I tried to save also a picture in the internet (using safari) and save to the server using FILE app. 

Same thing ERROR in saving.

(set the PHOTOS app setting to keep original)

Any ideas why it still causes such errors?

Thanks