Hello tintmaster,
Thank you for using Apple Support Communities! I understand that your Gmail account is not working on your new iPhone 11 Max. I would be happy to help point you towards a resolution.
I would like to have you start by going to Settings > Passwords & Accounts, then select your Gmail account if it's shown. On the next screen that appears, tap on your email address to the right of the word Account. You should then see a screen where you can view the email settings for this account. If you aren't sure which settings should be used, you can try to locate your email settings using the following link:
Mail Settings Lookup
If you're still encountering an issue sending emails from this account, here are some additional steps to take next:
If you can’t send or receive emails on your iPhone, iPad, or iPod touch - Apple Support
Cheers!