As I explained in this answer Even the great rationalists Maimonides and Gersonides assumed that the falling of the manna was miraculous. In fact, they assumed it was the most miraculous of miracles, on account of it being continuous for forty years. In addition to the sources I cited there, Gersonides also elaborates on this in Wars of the Lord Book VI Part 2 Chapter 7:
This accounts for the great difference between the miracles performed by Moses (may he rest in peace) and those performed by the other prophets. The former are quite encompassing, as is evident in the miracles of the plagues that spread amongst all the Egyptians. Moreover, they lasted for a longer interval; as for example, the miracles of the Manna and the columns of fire and smoke, both of which lasted some forty years. Such miracles are unique to Moses our Teacher (may he rest in peace). The miracle of the handful of meal and the little oil in the cruse that did last for some time was performed by Elijah for one woman only, nor was that time as long as the duration of the Manna and the columns of fire and smoke. Moses' miracles were extraordinary because of the continual isolation of his intellect [from the other capacities of his soul] in his apprehension, such that the providence emanating from the Agent Intellect was able to reach to him continually. Since his knowledge approximated the perfection of the Agent Intellect to a greater extent than any other prophet, the miracles performed by him were more encompassing and extraordinary. By virtue of the degree of his continual unification with the Agent Intellect these miracles lasted for a long time. This is what the Torah [itself] reveals concerning the differences betweent he miracles performed by Moses and those of the other prophets.
As such, it would be rather difficult to argue that the manna was actually a "natural" miracle, as if it was it wouldn't be the big deal that Maimonides and Gersonides make to out to be. Therefore, we presumably do not still see the miracle of the manna today.