Lead owner changing at conversion to Account - Sales Cloud

Hello,

I have noticed that some leads' owner (employee responsible) changes to the owner of the Account at the lead conversion to Account/Contact in Sales Cloud. I believe this is coming from lead routing determination rules. Is there a way to stop this happening at the conversion as this is affecting our lead KPIs? I have read in a forum that you can create a workflow to apply lead routing on create only but I am not sure how to do this. Any advice on this will be highly appreciated. Thank you!