Hi @Excel_aint , welcome to Q&A forum!
We can certainly use different accounts on the same device to use SharePoint.
If you are using SP online, I would suggest you use two different browsers, one for your work account and the other for your personal account.
If you must use only one browser, please make sure to sign out every time, clear the browser cache, close the browser and reopen it to log in to another account.
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