Hi Saarah04
welcome to this Apple (usr-to-user) Community!
Re: "Face time calls not coming through on my end when BF calls"
" ... does this mean it is an issue with his phone or mine? How can we fix this?"
It is not easy to guess what's up, with the details provided, so a few suggestions are listed below:
Perhaps one or another may help you restore order.
✽ It is often wise to check that iPhones are up-to-date with the newest compatible iOS version.
This often side-steps issues that arise. If you don't use "automatic" updates : you can always check in Settings > General > Software Updates at any time. NB: If you decide to update, it is always wise to back-up iPhone first.
✽ Settings > General > About will show you the version that is currently in use.
✽ The newest version for iPhone 15 Pro Max: About iOS 18 Updates - Apple Support says iOS 18.6.2
and "This update provides important security fixes and is recommended for all users".
✽ If for some reason you want to stay with iOS 17 as your post suggests you have now:
The newest version : About iOS 17 Updates - Apple Support says: iOS 17.7.7 is the latest version.
and again says:
"This update provides important security fixes and is recommended for all users"
✽ If your iPhone is already up-to-date and the issue with FaceTime is still a problem:
Try restarting your iPhone (deletes temporary files, re-establishes connections, may update any recent setting
changes, and often restores order if something is not working as expected.)
✽ FaceTime between Apple devices simply uses wi-fi.
If your boyfriend uses an Android phone:
He would need to use an internet link obtained from you to call you in FaceTime.
Eg: If needed: Create a link to a FaceTime call on iPhone - Apple Support
✽ You could check that you have a card for your boyfriend with his details listed in your Contacts app.
(Sometimes, for your privacy, a setting is in place to prevent calls from people not listed in your Contacts.)
All the best :-)