Experimental K$^\pm$K$^\pm$ invariant radii $R_\mathrm{inv}$ (a) and correlation strengths $\lambda$ (b) shown versus pair transverse momentum $k_{\mathrm T}$ for three multiplicity classes and compared with the EPOS 3 model predictions with and without the hadronic cascade phase. Statistical (lines) and systematic uncertainties (boxes) are shown. The points for lower multiplicity classes (blue and green symbols) are slightly offset in the $x$ direction for clarity.