You have multiple violations of CVX’s rules. If you ever got some version of R3 and R4 to be accepted, the final constraint would still violate CVVX’s rules. This model looks non-convex to me, although I have not completely ruled out that is may somehow net out to be convex.
If you don’t have a convex model, there is no hope of getting it accepted by CVX. Even if you do have a convex model, I;m not sure expressions such as R3 and R4 can be formulated in a way acceptable to CVX.