Are there any languages that are recursive but not context sensitive?
Yes. But it's complicated thing and it is not even taught in MTech Level Automata Theory Course.
CSL are accepted by LBA(Linear Bounded Automata). LBA are Non deterministic Turing Machines with tape capacity equal to the input string only.
So, LBA are NDTM with limited space (space is Not constant But space available is same as the length of the input string)
So, for any problem to be Recursive But Not CSL, means You can solve the problem by algorithm But you cannot solve the problem using only O(n) space complexity, where n is length of input string.
One popular such language is Set of pairs of equivalent regular expressions.
L = { <R1,R2> | R1,R2 are equivalent regular expressions}
L is Recursive But Not CSL.
https://cs.stackexchange.com/questions/273/decidable-non-context-sensitive-languages