As you will see from the Krypton 8.2.1 new post, samba has been upgraded (V4.x.x) read the note under heading in red for smb/samba, this also caused trouble for me and my asus dsl-ac68u, the reason the current firmware in the my router uses and older version of samba and so I get security issues from trying to login my 3tb hdd attached to the router.
As there is no firmware for my router (smaba V3) that can match libre's samba version release, I have to use a workround on my android box and RPI3 which is to create a text file in notepad or equivilent containing the below information to a file called user.conf , and it need placing in the folder listed in first line of its text. (the /xxxxxx/, might will be different from machine to machine i think)
;# place following in a file called user.conf in this folder /home/xxxxx/.kodi/.smb/
;# in gui set max proto to smbv1
[global]
client NTLMv2 auth = no
client use spnego = no
USING this though will reduce security of the samba link between the devices.
The last latest WD N900, firmware on their website is from 2015 i believe, so if it's built in smaba version is < v4 then this might explain your problem
Hope this helps
Andy