Good afternoon ardrilling,
Welcome to the Apple Support Communities!
I understand you are not seeing any information in the Calendar app on your iPhone XS. It sounds like you have iCloud enabled as you can see the information on your Mac and at www.icloud.com. Try quitting the Calendar app and restarting your iPhone as an initial troubleshooting step.
How to force an app to close on your iPhone, iPad, or iPod touch
If you have not already done so, update your iPhone to the most recent version of iOS:
Update your iPhone, iPad, or iPod touch
This resource provides some additional help with iCloud Calendar:
Get help using iCloud Contacts, Calendars, or Reminders
Take care.