Unavailable cellular data on my iPhone after iOS update

Lisaleese wrote: "It says 66% and it’s significantly degraded."

66% is not healthy and is to be expected in a 6 year-old battery. Have the battery replaced and then, with full battery power, your cellular data will probably become available:

iPhone Battery & Power Repair

About genuine iPhone batteries

Repair Provider Verification

(Articles found by searching Apple's Knowledge Base.)

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Lisaleese wrote: "Yes it does"

Okay, so your iPhone 7 still has its original 6 year-old battery. And to clarify my other question, this icon is the Settings app:

...Tap it and then scroll down to Battery and tap it. Then tap Battery Health and tell us what the Maximum Capacity % is.

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Did you follow the instructions in the Related Article above your name in your post? You should contact Apple Support if you see one of those messages. It also provides you with some troubleshooting tips and a link to Apple Support if you need to contact them.

That is correct. You need to contact Apple Support.

Lisaleese ~ Does your iPhone 7 still have its original battery?

And what's the Maximum Capacity % here?...

Settings > Battery > Battery Health

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