It is not my area of expertise.
But my reading of the enclosure suggests that Kodi 18 is not set up to use the older SMB1 network sharing protocol as a default. Due to security concerns.
The note suggests that provided the server (your pc?) is still using SMB1 (which it probably is) then you can alter Kodi 18 settings.
In android Kodi 18, go to settings - services - SMB client.
As suggested in the note,set both minimum and maximum protocol versions to SMB1 (from a drop down list)
Exit Kodi properly so the changes are saved then restart kodi
I have no idea if that will work but is my reading of the advice.