Readyshare Question

I have a RS280 router that I attached a 1TB hard drive to via the USB port.  The router recognises the hard drive and I can get it to show up in Windows 11 Explorer (most of the time!).  However, I cannot write new files or folders to it.  I do have permissions set to read/write with no restrictions in the router's GUI.  I have two questions:

1. Any idea why I can get the hard dribe to show up in Windows Explorer - but only periodically.  The share name is the default i.e. "\\readyshare\USB_Storage".  I have attached a screenshot of the ReadyShare Basic settings screen.
2. More importantly, does anybody know why I CANNOT write to the hard drive??  I tried mapping the network drive and connecting with no user or password - still can't write.  I tried mapping the drive and connecting with the user name and password of the router - still can't write.

I'm thinking I'm missing something pretty simple but just can't figure it out.

Thanks for any help or advise . . .