This works fine for me in ONTAP 9.8, provided I use a directory and not a file.
# mkdir dir1
::*> vserver security file-directory show -vserver DEMO -path /home/dir1
Vserver: DEMO
File Path: /home/dir1
File Inode Number: 31518
Security Style: unix
Effective Style: unix
DOS Attributes: 10
DOS Attributes in Text: ----D---
Expanded Dos Attributes: -
UNIX User Id: 0
UNIX Group Id: 0
UNIX Mode Bits: 755 UNIX Mode Bits in Text: rwxr-xr-x
ACLs: -
::*> cifs share create -vserver DEMO -share-name dir1$ -path /home/dir1
::*> cifs share show -vserver DEMO -share-name dir1$
Vserver: DEMO
Share: dir1$
CIFS Server NetBIOS Name: DEMO
Path: /home/dir1
Share Properties: oplocks
browsable
changenotify
show-previous-versions
Symlink Properties: symlinks
File Mode Creation Mask: -
Directory Mode Creation Mask: -
Share Comment: -
Share ACL: Everyone / Full Control
File Attribute Cache Lifetime: -
Volume Name: home
Offline Files: manual
Vscan File-Operations Profile: standard
Maximum Tree Connections on Share: 4294967295
UNIX Group for File Create: -
When I try to do it on a file:
::*> cifs share create -vserver DEMO -share-name file$ -path /home/newfile
Error: command failed: The specified path "/home/newfile" cannot be used. Reason: This is not a valid file-type for CIFS share.