In no time was there a mass exodus of people from Eqypt.
The historical record of ancient Egypt is far from complete... your negative assertion is not provable from that record on way or the other.
Absence of evidence is not evidence of absence... especially when you are looking for an event that occured in a very short time in a very long history of which we have only a very skimpy and interpreted record of heiroglyphics painted on walls to record the accomplishments of the latest Pharoah. Not once do we find a report of the failures of the latest Pharoah. It is particularly difficult when later Pharoahs were known for re-using walls, claiming the victories of others as their own, and sometimes completely obliterating the histories of Pharoahs they did not like. There are quite a few Pharoahs of whom the only thing we know of their existence is the name.
Egyptologist and even Biblical Archaeologists have barely even begun sifting the few records we have of Pharoahs other than Ramses II because for so long it was accepted fact that Ramses the Great was the Pharoah of the Exodus despite the mountains of obvious evidence that was mistaken. It is obvious why they found no evidence of a mass exodus of Semitic slaves or even of the slaves themselves during Ramses II reign because they were simply not there in the period they were looking for them, having left long before during the reign of Thutmosis IV (or as some have it, Thutmosis III) during an earlier, entirely different dynasty.