Opening the same application on a different desktop opens it on the desktop it was first used on. Microsoft, *please* let us use the same applications on different desktops.

I'm not the OP, but using the most up-to-date version of Windows 11 I have a very similar problem. If I open Excel, for example, by opening an Excel document on desktop 1, no problem. Now I switch to desktop 2 and I try to open a second excel document. Logic would say that since I'm opening it while on desktop 2 that that is where I want it to open. But no, it jumps back to desktop 1 and opens it there. So I drag the document to desktop 2. Now I close that document in desktop 2. Boom, I'm pulled back to the other open excel document, in desktop 1. Basically, I feel like I should never be pulled to a different desktop. If I'm in a desktop I should stay there unless I ask to change to a different one. But definitely with all microsoft 365 products I am pulled to the desktop where the app was opened. Chrome and Edge both work properly for me (as you note).

This is extremely annoying and defeats the whole purpose of multiple desktops. Microsoft please sort this issue out.

Chrome and Outlook seems to work fine - in that they open new instance of the app without switching back to the window with open open app. I see the problem with excel and ppt. Both of these want to switch back to the original window where the app is open. Very irritating.

Your reply on this question just reminded me about this issue so i decided to play with it and I just figured out how to do this myself (without the help of MS). Create a "new desktop" by opening the multi-desktop view and clicking the "+" button. You will see the original desktop with the new one next to it at the bottom of the screen with no apps open on the new one. All the apps that are open on the original desktop show up across the top of the screen, you may pull (drag and drop) any of those individual apps into "desktop 2" or "desktop3", etc. and only the window you drag and drop will open in the new desktop. So, if you have 4 different excel spreadsheets for different projects open in "desktop 1" you can go to that view and pull 1 or more of them into a different desktop so they are open there only, and the others will remain open in the original desktop.

This doesn't work with MS Excel which is the main product I want to use it with. Excel is MS's own native application, this should be a priority to make this feature useful, otherwise it serves no purpose for me and certainly many others.