I have recently downloaded the latest version of Office 365 on my new PC. I still have my old PC with a 2007 version of Office. It seems that if I switch between the 2 PCs working with outlook mail, the standard view in Inbox mail will not show mail that has just been in view in the other PC, i.e. : How can I at all times have the full view on both PCs all received e-mails. It is not that the mails are deleted, but I have to search for it to see it.
What is the service provider for your email (Outlook.com, gmail, etc.)? I don't remember, but maybe personal license also provide multiple installations per license (you can check in portal.office.com). Then maybe you can install new client on both PCs.