  The ratio of the $\mathrm{B}^0_\mathrm{s}$ and $\mathrm{B}^+$ fragmentation
fractions $f_\mathrm{s}$ and $f_u$ is studied with
$B^0_\mathrm{s}\to\mathrm{J}/\psi \phi $ and $B^+\to\mathrm{J}/\psi K^+$ decays
using data collected by the LHCb experiment in proton-proton collisions at 7, 8
and 13$\text{ TeV}$ center-of-mass energies. The analysis is performed in bins
of $\mathrm{B}$-meson momentum, longitudinal momentum, transverse momentum,
pseudorapidity and rapidity. The fragmentation-fraction ratio $f_\mathrm{s} /
f_u$ is observed to depend on the $\mathrm{B}$-meson transverse momentum with a
significance of $6.0\,\sigma$. This dependency is driven by the 13$\text{ TeV}$
sample ($8.7\,\sigma$) while the results for the other collision energies are
not significant when considered separately. Furthermore the results show a
$4.8\,\sigma$ evidence for an increase of $f_\mathrm{s} / f_u$ as a function of
collision energy.
