he newer OLTs have by default expiry time of 100 days:
MA5800-X7#display terminal user-profile

Crear USER OLT Huaweie
MA5608T>enable
MA5608T#config
MA5608T(config)#terminal user name
User Name(length<6,15>):smartispusr
User Password(length<6,15>):(put a strong password here)
Confirm Password(length<6,15>):
User profile name(<=15 chars)[root]:
User's Level:
1. Common User 2. Operator 3. Administrator:3
Permitted Reenter Number(0--4):4
User's Appended Info(<=30 chars):
Adding user successfully
Repeat this operation? (y/n)[n]:n


****IMPORTANTE*****
Crear ProFile OLT Huawei:
terminal user-profile add
User profile name(<=15 chars):smartisp
Validity period of the user name(0--999 days)[0]:
Validity period of the password(0--999 days)[0]:
Permitted start time of logon by a user(hh:mm)[00:00]:
Permitted end time of logon by a user(hh:mm)[00:00]:
Adding user-profile successfully
Repeat this operation? (y/n)[n]:n


By Rodrigo Anrrango 

Sistema de Administracion  OLT ZTE & Huawei
https://institutodewisp.com/olt/

Sistema de Administracion ISP con API Mikrotik
https://www.smartisp.us/