This Set-Cookie didn't specify a "SameSite" attribute and was default to "SameSite=Lax" - Localhost

Workaround: Downgrade Chrome

This is not a solution! just a temporary workaround for anybody like me how got his work halted due to this update.

• Uninstall ChromeGo to "Add or remove programs" and uninstall Chrome. Notice that user data like cookies and saved browser passwords may be lost.
• Download Chrome v90 from slimjet.com, or from any other site. Then install Chrome.
• Prevent auto-update Chrome, according to this StackOverflow solution:
  open C:\Program Files (x86)\Google\Update
  rename the file GoogleUpdate.exe to GoogleUpdate2.exe.
  This will cause Chrome to not find the update package.
• Update Flags - Open Chrome and type: chrome://flags
  Search #same-site-by-default-cookies and Disable the flag

In our case, we are able to also run our server locally on a different port and point our client app to that localhost address for development purposes.

For example, I have the client app running on localhost:1234 and sending requests to a local copy of the server running on localhost:5678. This ensures that cookies are set successfully since the client and server are now "SameSite".

Admittedly, this is perhaps more of a workaround than a solution, but I hope it helps in the short term.

I have found a way to fix it and share it with everyone :-)

Description appears in the issues section:

Specify SameSite=None and Secure if the cookie should be sent incross-site requests. This enables third-party use.

In the Developer Tools section, go to the Application tab, and on the left side to Cookies:

The cookie that you want to share with other domains, mark the Securecheck and in Samesite put None. Update the site tab locally and youwill be able to use the cookies that allow you to send through thedomain of origin

I hope this brightens your day