We are unable to recreate this on our testing devices. Have you attempted to wipe the cache partition of the device? Do you have the official Microsoft Office app?
So here is what's going on...I actual had this problem when I did Smart Switch from my Note 9 to my Note 10+. The apps worked in Dex mode on the Note 9 but on the Note 10+. I finally just did a factory reset on my 10+ and then everythings worked in mobile and in Dex. Last week set up Link to Window and now the apps (PP, Word,Excel) will not open in Dex mode and only in mobile. As you as you click on the program it immdeiately closes. I think is may have something to do with the fact I have a Hotmail acct that does no have the Microsoft license and I have an office365 account that does. When I set up my Link to Windows I used my hotmail acct. I reset the apps in mobile version and deleted the hotmail acct. Ialso shut of Link to Windows and the apps will still not open
I found out what the conflict is. The Multi-window screen zoom setting in the Multistar App withing Good Lock. Disable this feature when using Dex and Excel and Word will work again. Another user reported that just uninstalling Good Lock will fix it, but if you like the other features offered by Good Lock simply disable the feature I mentioned above.