However I am always able to log on with their credentials from my computer (Mac).
What could be causing these problems?
If it works for you but does not for them using the same credentials, the issue points to something in their environment. I would make sure they allow the subdomain in their firewall rules. It could be failing to authenticate due to a block in traffic.
Let me know if you have any further questions or concerns and I will be happy to assist you with the issue.
If you are unable to login to your account, open yourdomain.sharefile.com and click the Forgot password link.
Refer to CTX238137 - Unable to login to My ShareFile Account, Password Not Working for more details
Citrix identified some unusual logins to certain Citrix ShareFile (aka. Citrix Content Collaboration) user accounts. We are requiring a password reset for all non-SSO accounts. Upon logging into ShareFile, users will no longer be able to use their old password. They will have received an email providing a link to reset their password.For more details on the recent password policy change, refer to Citrix forces password reset to protect against credential stuffing