In Between $T_1$ and $T_2$, Albert Wilansky mentioned in 6. that it was not known whether or not every locally compact US space is $T_2$.
Is this matter still an open problem?
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No, it is not. S. Franklin gave an example in his review of Wilansky's paper: take a compact space with a point $x$ that is not the limit of a non-trivial sequence, for example the ordinal $\omega_1+1$ with $x=\omega_1$, and double that point. The set of our space is $\omega_1\cup\{\omega_1^a, \omega_1^b\}$; the points other than $\omega_1^a$ and $\omega_1^b$ have their normal neighbourhoods and the (basic) neigbourhoods of $\omega_1^i$ ($i=a,b$) are $(\alpha,\omega_1)\cup\{\omega_1^i\}$ with $\alpha<\omega_1$.
The result is US and (locally compact), but not Hausdorff.
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$\begingroup$ Do you have a reference for Franklin's article? $\endgroup$– PelusoCommented Oct 27, 2021 at 17:17
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$\begingroup$ The link points to his review in Mathematical Reviews; I don't know if he published this anywhere. $\endgroup$– KP HartCommented Oct 27, 2021 at 17:37
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2$\begingroup$ That was the issue, thank you for your patience and for the copy. $\endgroup$– PelusoCommented Oct 27, 2021 at 18:12