Is it normal for blood vessel to fade immediately after IPL then come back after 3 days?

Unfortunately, yes, this is common. The reason is that IPL can send blood vessels into spasm and so they contract and disappear only to reappear later. The other issue is that most IPLs have wavelengths in the 600 and up range, and hemoglobin (blood) is only treated effectively in the 500 range. The only IPL I know of currently that is in the 500 range is the InMode Lumecca which I have found to be far superior to all other lasers I've had (and I've had about 17 different brands over the years). So many times IPL is not the best treatment for larger blood vessels. "This answer has been solicited without seeing this patient and
cannot be held as true medical advice, but only opinion. Seek in-person
treatment with a trained medical professional for appropriate care."

Unfortunately, blood vessels can be stubborn. It is not uncommon that vessels need to be treated with lasers more than once to make them go away. Often, settings on the laser need to be increased to treat recurrent blood vessels more aggressively.