iPhone X keeps losing cellular data

Kadwhitt ~ 75% is not healthy. Apple recommends replacing the battery at around 80%. The weak, aging battery is very likely to be cause of losing cellular connection. Have the original battery replaced and all will (probably) be well:

iPhone Battery & Power Repair

About genuine iPhone batteries

Repair Provider Verification

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

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Kadwhitt ~ Does your iPhone X still have its original battery?

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

Settings > Battery > Battery Health

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