No logs, no accurate description of before/after changes to SMB settings, and not enough technical detail to do anything beyond guess at the issue:
a) Your hardware might have NICs that need odd drivers to work
b) Your SMB server needs different settings, or Kodi client isn't configured correctly
I'd guess it's the later .. but .. it's just a guess
btw, LE *never* auto updates between Kodi major versions, so it was your decision to manually upgrade.