Hi Stephen,
I believe that's a very common issue.
I see it all the time because I'm flipping between tenants with different user ids.
You will probably find it goes away if you switch to incognito/private browsing, because then your cache history is not being used.
The way I deal with it isn't perfect, but I set my browser security settings to clear cache every time I exit my browser.
I've heard others deal with it by using Firefox where they provide a type of containers/virtualization between browser tabs.
References:
https://support.mozilla.org/en-US/kb/how-use-firefox-containers