This issue doesn’t happen in Windows or in Android Kodi versions, it only happens in OSMC Kodi 17 and 18 builds I’ve tested.
If Kodi can’t get the metadata from the source (a DLNA server) in OSMC version it shows (1969), but in other versions nothing it’s showed probably because it detects that the tag hasn’t a valid value (or it’s empty) while some routine in Kodi OSMC builds the value it’s initialized to a non-empty default value (1969), hence, it’s showed in the Kodi interface as a valid date.
This may be a limitation of DLNA/UPnP… The implementation in Kodi has always left a bit to be desired and iirc, there were always issues with metadata. You should try with samba and see if the behavior is the same. Otherwise, you should probably address this issue directly with Kodi developers.
It isn’t a generic Kodi issue because other Kodi versions in other platforms behave correctly. Only over OSMC this tag is incorrectly initialized when the value isn’t available.
I’m using Vero 4k (I forgot to mention) and it happens with all skins I’ve tested.
And, as I’ve said, if at least two other builds in very different platforms as Windows and Android detect without issues when that tag isn’t available it can’t be a generic Kodi bug.