PowerPoint opens linked files in edit instead of show mode.

I use a lot of file links in PowerPoint. Sometimes these links are multilayered. That is, the linked file includes more links. Until recently (last month or so) this was no problem. However, now when I select a link, it opens the linked file in edit mode instead of show mode. And it shows it on my presenter screen, not my show screen. I have to manually select show on the link file to get it on my show screen. That defeats the entire purpose of a link. When you are in a presentation, and click a link to another file, why would you want it to open in edit mode? And why doesn't it open on the show screen? This is really annoying. This only occurs on one of my computers (a Windows 10 desktop). It doesn't act the same on different computers. I have a desktop and two laptops. The desktop and one laptop are Windows 10, and the other laptop is Windows 11. Both laptops work properly and open the linked files in show mode. But the desktop opens the linked file in edit mode. These are the same files. In fact I can run the files from my laptops on my desktop via my network, and it works the same way. I have the same Office 365 on all three machines. I've been using PowerPoint for many years, and never had a problem with links before. What's changed? I also have hundreds of files with links. I have no desire to convert all of them to ppsx files. By the way, I tested going to ppsx files, and it didn't work. It does open the linked file in show mode on my show screen. But it also opens the linked file in edit mode on my presenter screen on top of my calling program file. That's also annoying. I even uninstalled Office 365 and reinstalled it on my desktop with no improvement. The bottom line is that it works correctly on most of my computers, but not all. Is there some setting that I'm missing? I couldn't find any.