"Unable to determine if your iPhone battery is a genuine Apple part"
[Re-Titled by Moderator]
iPhone XS Max, iOS 15
[Re-Titled by Moderator]
iPhone XS Max, iOS 15
Either the battery is failing or you had the battery replace by someone other than Apple or an authorized service provider.
If you did not have the battery replaced, make an appointment at the Genius Bar of your local Apple Store. if you did, and it was not done by Apple or an authorized service provider, you’ll have to live with that or buy a new phone. Apple won’t touch it.
"Unable to determine if your iPhone battery is a genuine Apple part"