Creating users but credentials not working

When I create a user (username, password), and then try logging in with those credentials, it doesn’t work.

Very frustrating, as I need to add several users to a restricted area of our site today and don’t want them to go through the hassle of registering themselves (so just want to give them the logins that I create as admin). Need to resolve this ASAP!

https://ww.wp.xz.cn/plugins/pie-register/