Hi Sean F1,
When navigating to Settings > Maps, is the option for "Share ETA" turned on? If so, are you able to use Siri to share your ETA?
"Share your estimated time of arrival (ETA)
Siri: Say something like: “Share my ETA.” Learn how to ask Siri.
Or without asking Siri, you can do the following:
- Tap the route card at the bottom of the screen, then tap Share ETA.
- Choose one or more suggested contacts, or tap Open Contacts to find a contact."
That information and additional helpful details can be found here: Things you can do while following a route in Maps on iPhone
You can also check to see if you have enabled the Driving Focus feature, and if ETA works as expected with this turned off.
Stay focused while driving with iPhone
If all settings are correct, force close the Maps app and complete a normal restart of your iPhone to test sharing your ETA again.
It should be listed as the guide pages shared above are for iOS 15. Keep us posted on what you find.
Best!