Same issue here. Outlook, Teams files, Microsoft Company Portal app, all of the same behavior. I had not dug in that deeply as we have a limited number of the Precisions, and it was intermittent. However, it causes bluescreens from time to time. Took a look at the crash dump this morning an it pointed to the driver for Express Connect - ExpCo10X64.sys. Checked Dell for updates to my drivers and Dell applications, nothing newer than what I had installed. Uninstalled Dell Optimizer 2.0 eliminate this program. Kudos to posting this. Thanks
The Dell Optimizer update that was released at the end of April is causing issues with Outlook in our environment.  I'm just writing this to hopefully save others some grief if this occurs elsewhere. After the upgrade, Outlook will either disconnect every few hours or get stuck at loading profile.  The only way to resolve it is to restart the PC.  This has happend on Precision 5760 & 7550 models as well as Latitude 7420.  Uninstalling ExpresConnect from the Add/remove programs applet resolved the issue for several in our environment. Just hoping that if anyone else has this issue this will help. It took me about 7 hours to figure out what was causing it!
ExpressConnect/Outlook Issue