Iwasawa theory and mock plectic points

We use Iwasawa theory, at a prime $p$ inert in a quadratic imaginary field $K$, to study the arithmetic properties of mock plectic invariants for elliptic curves of rank two. More precisely, under some minor technical assumptions, we prove that the non-vanishing of the mock plectic invariant $\mathcal{Q}_K$ attached to an elliptic curve $E_{/\mathbb{Q}}$ of even analytic rank $r_\mathrm{an}(E/K)\ge2$, and with multiplicative reduction at $p$, implies that the $p$-Selmer rank $r_p(E/K)$ equals $2$. The proof rests on one inclusion of Perrin-Riou's Heegner point main conjecture for elliptic curves with multiplicative reduction at $p$ which we obtain using bipartite Euler systems.