Sharepoint migration connected Excel Queries

we have a problem at work that we can not find out, we ran Sharepoint migration manager and moved from onprem server to sharepoint online. Questions arose regarding EXCEL links if they still work after moving to sharepoint. We tested some excel sheets that had been moved to sharepoint, these turned out to have changed automatically from link to H: // share / HR / excel link to  link "Sharepoint.company.com/sites/HR-bibliotek/EXCEL"…. Does this mean that sharepoint migration manager is changing all connected links to files connected that has been moved to sharepoint?
I need to find som facts that sharepoint migration manager or excel workbooks change these connections to the files that have been moved to sharepoint online.