Shell evolution in nuclei far from stability is understood to arise from the complex interplay of orbital interactions, with different interactions accessible in unstable nuclei compared to those near stability. Experimental studies of these exotic regions provide stringent tests of modern shell model interactions, but are difficult to access experimentally. In this regard, the transfer reaction 47K(d,p)48K provides a unique opportunity to study the exotic π(s1/2)-ν(fp) interaction in a near-doubly magic nucleus, owing to the π(s1/2)-1 ground-state structure of 47K, which is near-degenerate with the ‘standard’ π(d3/2)-1 proton configuration in this region. The first measurement of the 47K(d,pɣ)48K transfer reaction has been performed at GANIL, using the combination of MUGAST+AGATA+VAMOS. The results of this study, supported by the simultaneous measurement of 47K(d,tɣ) and 47K(d,d), are compared with SDPF-U and SDPF-MU shell-model calculations to reveal a number of striking discrepancies. Intriguingly, an apparent systematic overestimation of spectroscopic factors and a poor reproduction of the energies for 1⁻ states suggest that the mixing between the π(s1/2)-1 and π(d3/2)-1 proton configurations in 48K is not correctly described using current interactions, challenging our descriptions of light N=28 nuclei.