locating and creating file windows 2008 Server R2 using WIndows 10

I feel a l little embarrassed asking this question but  I searched the net for a couple of days with no solution

I created a share on our  windows 2008 Server and and then created a  folder (lets call it Newly Created).
I moved files into this folder from another location and all was fine.
Then another user created 2 folders within that folder( lets call it folder a-m and folder j-z) inside the Newly Created.
I am able to create/delete and edit files on the l-z folder, but the a-m I cannot create a folder in that directory.
I can create a folder in an already created folder within a-m but not a new folder.
j-z folder allows me to change or add/delete anything in that folder.

I am not sure what is happening, I am able to say new folder and it hightlights the text to name it and then it disappears. I actually see the folder get created and see it disappear before being able to rename it.
Few things I have tried, checked permission of folder againt l-z and all match.
Tried different users, doesn't work for a windows 10 user or administrator.
Checked to ensure there is not an invalid character in folder name.
I am at my wits end and need to resolve asap.
thanks