Map the SharePoint to a drive letter and access it like a NAS.
Open Internet Explorer (not Edge, not Chrome, not Firefox). If you can’t find IE then ask Cortana to find it.
Go to the Office 365 login. Tell it to remember you and automatically sign in to avoid sign in over and over.
Login and go to the documents page of the SharePoint site that you want to make into a Mapped Drive.
Click on the “All Documents” with the down arrow the select “View in File Explorer”. This will needlessly open a new browser tab and, also, open the site in a Windows File Explorer window outside of your browser.
Right click the address and select “copy address”.
Then you can open a new file explorer and start a Map a Network Drive using the copied link as the folder. Also Choose the reconnect at sign in tick box.
In the future any time it won’t connect likely your signed out in IE open Internet Explorer and sign in again.