$Path='C:\temp'
#remove-item "$Path\TestPS"  -recurse
md "$Path\TestPS"
get-childitem -path "$Path\TestPS\F*.txt" -File -Recurse #OK no file

md "$Path\TestPS\D1"
get-childitem -path "$Path\TestPS" -Directory -Recurse #Ok one directory
get-childitem -path "$Path\TestPS\*" -Directory -Recurse #NOK no result

"Test" > "$Path\TestPS\D1\File1.txt"
get-childitem -path "$Path\TestPS\F*.txt" -File -Recurse #OK one file
get-childitem -path "$Path\TestPS" -File -Recurse #OK one file

get-childitem -path "$Path\TestPS\*" -File -Recurse #NOK no result

#Add a file into the 'root' of the search 
"Test" > "$Path\TestPS\File2.txt"
get-childitem -path "$Path\TestPS\*" -File -Recurse #OK two files !!! Different !!!
get-childitem -path "$Path\TestPS\*" -Directory -Recurse #OK one directory !!! Different !!! 


remove-item "$Path\TestPS\File2.txt"
#The 'root' of the search is empty 
get-childitem -path "$Path\TestPS\*" -File -Recurse #NOK no result
get-childitem -path "$Path\TestPS\*" -Directory -Recurse #NOK no result

#original path
#Get-ChildItem -Path 'C:\Users\laurent\AppData\Local\Mozilla\Firefox\Profiles\*.default*' -File -Rec

#it works
#Get-ChildItem -Path 'C:\Users\laurent\AppData\Local\Mozilla\Firefox\Profiles\*.default*' -Rec|Where-Object {-not $_.PSIsContainer}

get-childitem -path 'C:\Temp\TestPS\*" -File -Recurse
get-childitem -path 'C:\Temp\TestPS\*" -Directoyr -Recurse

> $PSVersionTable
Name                           Value
----                           -----
PSVersion                      6.0.0-beta.9
PSEdition                      Core
GitCommitId                    v6.0.0-beta.9
OS                             Microsoft Windows 6.1.7601 S
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0, 5.0, 5.1.10032.0, 6.0.0}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

> $PSVersionTable 
Name                           Value
----                           -----
PSVersion                      5.1.14409.1012
PSEdition                      Desktop
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0, 5.0, 5.1.14409.1012}
BuildVersion                   10.0.14409.1012
CLRVersion                     4.0.30319.42000
WSManStackVersion              3.0
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1