Could not refresh the token in OIC/VBCS BO REST Call

Summary:

We have set up Client Application for VBCS/OIC Instance for OAuth2.0 in IDCS and considered below authorization types

Client Credentials

Resource Owner

Refresh Token

Now When we set up OIC Connection with Resource Owner type security policy , for the first hour , Integrations work fine but it fails after that with error as

"Target REST Header End point could not set …….Could not refresh access token" . Snippet Attached.

Based on Doc ID 2799485.1 , It is suggesting to use Custom 2 legged Security policy instead of Client credentials/ Resource owner.

So the question is

1. Does using Custom 2 Legged Security Policy allows the connection to refresh automatically which does not happen for Client Credentials/ Resource Owner ?