  Let $U,H$ be two separable Hilbert spaces and $T>0$. We consider an SDE which
evolves in the Hilbert space $H$ of the form \begin{align}
dX(t)=AX(t)dt+\widetilde{\mathscr L}B(X(t))dt+GdW(t), \quad t\in[0,T], \quad
X(0)=x \in H, \end{align} where $A:D(A)\subseteq H\to H$ is the infinitesimal
generator of a strongly continuous semigroup $(e^{tA})_{t\geq0}$,
$W=(W(t))_{t\geq0}$ is a $U$-cylindrical Wiener process defined on a normal
filtered probability space $(\Omega,\mathcal{F},\{\mathcal{F}_t\}_{t\in
[0,T]},\mathbb{P})$, $B:H\to H$ is a bounded and $\theta$-H\"older continuous
function, for some suitable $\theta\in(0,1)$, and $\widetilde{\mathscr L}:H\to
H$ and $G:U\to H$ are linear bounded operators. We prove that, under suitable
assumptions on the coefficients, the weak mild solution to the equation depends
on the initial datum in a Lipschitz way. This implies that pathwise uniqueness
holds true. Here, the presence of the operator $\Lambda$ plays a crucial role.
In particular the conditions assumed on the coefficients cover the stochastic
damped wave equation in dimension $1$ and the stochastic damped
Euler--Bernoulli Beam equation upto dimension $3$ even in the hyperbolic case.
