On iOS14 or later, the body of push notifications is cut off at around 256 characters. For iOS13 or earlier, the entire body was displayed normally and the issue did not occur. Do you have any idea of the cause, such as a change in Apple's APNs or OS specifications?
There is a limitation that "APNs support only 4096 bytes for the entire payload of a push message," but the notification size when an event occurs is 4096 bytes. We have confirmed that the size of the notification when an event occurs does not exceed 4096 bytes. Are there any other restrictions on the number of characters used to send push notifications?