Sitename sometimes point to 1270.0.1:8000

I am using Seafile Pro 6.2.10. Today i wanted to activate the Two-Factor Auth and after scanning the QR code, it will be listed as “127.0.0.1:8000” instead of the real sitename.
This affects the password forget mail - the subject is like “Password reset for 127.0.0.1:8000”

Any ideas how to fix this issue ?