Analyze in Excel and Account Sign Out

Hello, I apologize if this question has already been asked, but I did not find this specific scenario anywhere.

If I log into my Power BI work account from my personal laptop, I can use the "Analyze in Excel" feature to create a pivot table or do other analysis in Excel.  That works perfectly.  What concerns me is that even after I sign out of my Power BI account, both on the Power BI site and in Excel directly, I'm still able to refresh and filter the data from my work dataset.

Is there a way to actually sign out of the data connection once the datasource has been set up?  The only way I could think of to do it was to delete the excel file altogether.  If this is the only way, then this seems like a pretty big security flaw, since it would be pretty common for someone to access their account from both within and outside the organization, for various reasons.  Think of a shared family computer or a conference room PC.  I understand that there are other things you could do to secure the Excel file itself, like use different windows logins on those PCs or password protect it, but it seems like the data connection in Excel should authenticate each time using the current signed-in account, or prompt you to sign in if you currently are not.

Thank you in advance, I am relatively new to the Power BI service, so hopefully I am missing something obvious.