Finder thinks item exists after it's already been deleted (Samba)
Finder caches file/folder metadata from SMB shares. Try if disabling the directory caching helps according to the last paragraph in:


Adjust SMB browsing behavior in macOS High Sierra 10.13 and later



  Disable directory caching
  
  Your Mac caches file and folder metadata temporarily in local memory. This improves browsing speeds, especially on high-latency networks. Systems with more memory installed can cache more file information.
  
  If you'd like to disable directory caching so that macOS re-downloads the full contents of the folders and metadata every time you browse an SMB share, you can create or edit /etc/nsmb.conf. See the nsmb.conf man page for more information on how to edit this file.
  
  If your system doesn't already have an /etc/nsmb.conf file, use the following Terminal commands. Note that you must be logged in as an administrator with sudoer privileges to set this file:
  
  echo "[default]" | sudo tee -a /etc/nsmb.conf
  
  echo "dir_cache_off=yes" | sudo tee -a /etc/nsmb.conf


Unmount/remount SMB shares afterwards.