Why are there no planetary occultations visible from Earth between 1818 and 2065, when otherwise they are comparably frequent?
There is nothing unusual about the period 1818-2065, planetary occultations are rare events.
Planetary occultations are rare events. The reason for this is that is that all of the planets' orbits are in a slightly different plane. For an occultation to occur, the Earth and two other planets need to be a line.
Occultations often follow a pattern by where two planets occult twice with a relatively short interval between them. The pairs of occultations don't occur again for centuries.
Some centuries such as the 1700s and 2000s have 4 or more occultations. Other centuries such as the 1900s have none. The interval 1818-2065 had no occultations because there are long intervals between occultations of any pair of planets this interval was between events. There will be future periods of similar length with no events.
Interestingly the 2065 occultation of Venus and Jupiter will not be visible as it occurs too close to the sun to be observable.