If an Opportunity is created from a Lead, the Lead becomes disabled. If the Opportunity is lost, the Lead seems to stay disabled.
If a sales agent re-engages that Lead, what record should they use?
Are they supposed to create a new Lead record? What if they want to update some details from the Lead? Do they edit the Contact record instead?
Can you share the version you’re on?
Ideally, the flow in most CRMs (and now ERPNext) is as follows:
Lead → Account/Contact → Opportunity.
When creating an Opportunity, the lead should become unusable with the details migrated to Contact and Account documents.
If the Opportunity is lost, the sales person should be able to re-open or create a new Opportunity to pursue the new business opportunity that comes along.