Cart API issue : 500 error and merge cart not triggering :

[printuidocs]

Spartacus version : 5.2.x

LoggedIn from third party application

After received token information from 3rd party application , doing two steps to make user as LoggedIn user

Issue 1)
this.userIdService.setUserId(OCC_USER_ID_CURRENT);
this.store.dispatch(new AuthActions.Login());

When loading cart API , {doamin and base site}}/users/current/carts/9d9ejfjs90a9d9f
Here application taking userId as current and taking cart id as Anonymous Id and finally throwing 500 error

Issue 2)

If there is any anonymous cart merge cart API , not triggering after changing user type as current