I would expect the suggested name ends with a '\' if it's a directory, so I can continue to type in the first letters of the next name down the path, and use tab again. I don't know when it started, but on one of my PCs, Powershell just won't add the slash. It's been painful to type all the extra '\'s. Does anyone know if there's a setting?
I got my Powershell back to normal after I followed the instructions here to get it working with core method calls.
Running the following command doesn't bring back the "bug" like before.
$ExecutionContext.SessionState.LanguageMode = "ConstrainedLanguage"
But setting that __PSLockdownPolicy registry key back to 4 does.