need to sign in microsoft every time I open a new Word document.

[garyjulian100]

How can I avoid this real inconvenience? The sign-in yellow ribbon shows up on top of my newly opened doc and if I ignore it I can't use Word features.

[#2]

Go to file - account and see if you are properly logged in!
Seems like strange behavior, try do a online repair from the control panel

[#3]

@garyjulian100 

Have you changed your password before? Try removing locally stored password in your machine.

To remove the user credentials from Credential Manager:

1. Click Start > Control Panel > User Accounts > Credential Manager.

• Note: If 'View by' is set to Category, click User Accounts first, and then click Credential Manager.

2. Select the Windows Credentials option. Locate the set of credentials that has Microsoft Office in the name and then expand the corresponding folder.

3. Then click Remove from Vault or Remove (depending upon which version of Windows you are running).
4. Repeat step 3 for any additional sets of credentials that have the word Microsoft Office in the name.

Try opening any Office apps again then sign in again.

The next time you close and open the apps, it should not ask for credentials