Problem with networking between W-8.1 computer & W-10

I have a W-10 laptop that I can connect to my other computers, but only from the other computer, not vice-versa. The icon of the other computer shows up on the network window of the W-10, but when I click on the icon, I am prompted to enter my credentials - but the password is not accepted. From the other computers, the W-10 icon appears and when it is clicked, the shared folders on the W-10 are displayed without being asked for credentials. Files can be transferred to and from the other computer when operating from there. The other laptops that work this way are running W-7 and W-8.1.
Am I doing something wrong?

I have what sounds like a similar problem. I have completely dismantled and recreated my homegroup three times now, stopping and disabling the two Homegroup services and disabling their startups on all machines before rebooting and setting it all up again. Win 10 systems are communicating between each other just fine but the one 8.1 system gets asked for a username and password when it tries to connect, but these do not exist in a homegroup of course. This also happens in the other direction, when a Win 10 system tries to connect to the 8.1 system.