Charging on hold when iphone on normal Temreture

Normal temperature is relative. When you fast charge an iPhone the battery inside the phone gets warm; it will pause at 80% to allow the battery to cool down before it resumes. This delay can be up to an hour, depending on how heavily you are using the phone.

Another possibility is Optimized Battery Charging→About Optimized Battery Charging on your iPhone - Apple Support

This could be because of your charging unit, environment, battery, etc.

iPhone will give you the notification when it’s too hot or too cold to charge. Does this happen every time or just once?