Been dealing with the same thing on 5520's on Windows 10. I just found this form post today that I think may be the issue.   "We found out what the issue is with the laptops and office/teams. the issue is resolved when you stop working with your ethernet and Wireless connection connected. When we started a trace we found out that we had two gateways from the devices and that gives an hiccup to the office applications. we changed in the BIOS a setting that is called Wireless Radio Controll. WRC is by default off but when you put in on, it will detect when an wireless connection is needed or not. now that we put that to the test we see that the issue is resolved. the only thing we notice is that wireless on is quicker then wireless off, but that is not an issue for us." [URL] So far in my testing today this seems to have fixed the issue.   
Latitude 5520. My company has a very disturbing issue with multiple Latitude 5520 laptops, all behave the same way, they have all Windows 11 and Office 365. Excel constantly crashes or hangs, if you close Outlook you have to reboot the computer in order to re-open it because it freezes on loading. All updates both software and hardware are installed. We have uninstalled Office 365 and reinstalled it, but the problem persists. Thank you  
Latitude 5520 and Office 365