This has been discussed earlier on this forum. His son stated it was wrong since he never went to Egypt.
Allamah Kashmiri never visited Egypt, in his entire life. This is clear from his biographies and was mentioned by his son, Ml. Anzar Shah Saheb, when he visited South Africa a few years ago. Also, Nur al-Idah was in the subcontinent years before that. Ml. Abd al-Hay al-Laknawi (d. 1304 ah) had the book, as well the commentaries on the book written by Allamah Shurunbulali. Sadly, this story is extremly famous in all madrasahs and is religiously repeated to every class studying Nur al-Idah. We also heard it repeatedly and if it wasn't for some of our teachers asking ml. Anzar Shah about it, we would have also been repeating it to our pupils. There are numerous other reliable stories about Allamah Kashmiris memory, so this one not being quoted shouldn't be a problem.