SMB issues 13.0-U3.1... but it works in 12.0-U8.1

[dust_bro]

I recently upgraded from 12 to 13 and ran into an issue with my SMB shares. It appears that I'm able to write to the share, but I don't have the ability to read the data I just wrote. Using the same exact settings in 12 works as expected.
EDIT:
After poking around, it seems setting the ACL Mode to Restricted cures this issue. It doesn't work that way in 12 so this one was stumping me.

 

[dust_bro]

I take it back. Not cured. Unexpected user permissions are applied.

 

[anodos]

Please PM me a debug.