If you are only unable to get the speaker working on your new router, then I do agree that it is likely a setting on the new router stopping you from using the speaker. I'd recommend starting by making sure the settings of the new router match our recommended router settings HERE, so it is optimized for use with the speaker.
Thanks for going through this! Not all router settings will be the same or have the same titles, so don't worry that you can't find that section. At this point, I recommend contacting our support team via phone. This will allow for a much more complex dive into what's happening with the connection. Our team can even remote access in to see if anything can be tweaked. You can do this by clicking Global Contact Us > Select your country > Scroll to the bottom of the page > Click 'Contact Us'.