Hello,
You’ve mixed two approval models. That’s why Sandbox 1 behaves differently.
What’s happening
Approval User Setup = hierarchical approver (mandatory if used)
Workflow User Group = workflow-driven approvers
If Approval User Setup exists for the requester, BC always uses it first and ignores the workflow user group.
In Sandbox 1, the user has an Approver ID → approval goes only to that person.
In Sandbox 2, that setup is likely missing, so the workflow user group works.
Fix / Best practice
If you want Workflow User Group approvals:
Remove Approver ID for the requester in Approval User Setup
Keep only:
Workflow
Workflow User Group (User A → User B sequence)
If you want manager-style approvals:
Use Approval User Setup only
Don’t use workflow user groups
Rule of thumb
> Don’t mix Approval User Setup and Workflow User Groups for the same document type.
Docs:
Approval workflows overview
https://learn.microsoft.com/en-us/dynamics365/business-central/across-how-to-set-up-workflows
Approval User Setup behavior
https://learn.microsoft.com/en-us/dynamics365/business-central/finance-how-workflows-approvals
Regards,
Oussama Sabbouh