converting lead to an opportunity

Summary:

Not able to convert a lead to an opportunity

Content (please ensure you mask any confidential information):

Hi,

One of the salerep is not able to convert a lead to an opportunity.

while looking into it in more detail, found that, the salesrep was not owner of one of the activity.

After changing the activity owner to the salesrep, it allowed to convert.

We would like a salesrep to convert leads to an opportunity, even if they are owners of dependent objects like contact, ativities etc.

Is there any role missing. People with sales admin role are able to convert leads to an opportunity.