Office screen at boot-up?! Why? What's it doing?

Always creeped out by Microsoft's habit of locking you in and making you sign in and subscribe. I'm not doing that! I have a local Windows accout and am not signed into Office. I use the Desktop version of Office, the latest available, I believe, which is Office 2019.

I used this version of Office on Windows 10 too, but never experienced the behaviour I want to ask about. Here it goes:

When booting up Windows 11, the boot-up process stops for maybe 20 seconds (it feels really long!) on a blue and white screen with some Office program icons. It's not saying Office, and it's not explaining what it's doing - but I recognise the icons of course.

Is this a known behaviour?
What's this about? What is it doing?

Hello. I don't understand what you are seeing. Could you provide a picture of what the screen looks like? You probably won't be able to use screen shot but, you could use a camera or your smartphone if you have one and post a picture.