Hey Drwoodr,
Thanks for using Apple Support Communities! I understand you're running into an issue with your Favorite Map locations syncing across your devices. I definitely want to make sure that information is available on both your devices, and I'm happy to help.
To start, let's make sure that Maps is fully updated on your iPad. You can see how to do that here: Update apps or use automatic downloads
If all your apps are updated, check out on both devices that in [Settings > Your Name] > iCloud, you have Maps enabled (showing green) there.
Another great setting to check is that Low Power Mode isn't enabled on either device. You can check and change this if necessary in Settings > Battery.
You may also want to consider updating to the latest version of iOS 13 if you haven't already done so. You can see how to do that here: Update your iPhone, iPad, or iPod touch
Thanks again, and have a great day!