Towards an improved understanding of S. Holz, J. Plenter, C. W. Xiao, T. Dato, C. Hanhart, B. Kubis, U.-G. Meißner and A. Wirzba Eur. Phys. J. C, 81 11 (2021) 1002 Published online: 13 November 2021 DOI: 10.1140/epjc/s10052-021-09661-0