Unable to login to amster after changing default authentication service


I am working on Identity Platform setup where I have changed the default authentication journey for both admins and organization. I am able to use the new default journey successfully while using the ForgeRock platform login UI, and am able to login as amadmin. However amster login fails with the below error.

User Name amadmin
Password **********
Could not connect to OpenAM server at http://********:8080/****
Reason: null

I have added a logger statement in my authentication journey. However, I am not able to see the logs in the AM logs when I try a login through Amster.

I was wondering which login service is being used by Amster? And if there a way to make it work with a custom default journey?