  Radio-loud active galactic nuclei (RLAGNs) are rare among AGN populations.
Lacking high-resolution and high-frequency observations, their structure and
evolution stages are not well understood at high redshifts. In this work, we
report ALMA 237 GHz continuum observation at $0.023''$ resolution and VLA 44
GHz continuum observation at $0.08''$ resolution of the radio continuum
emission from a high-redshift radio and hyper-luminous infrared galaxy at
$z=1.92$. The new observations confirm the South-East (SE) and North-West (NW)
hotspots identified by previous low-resolution VLA observations at 4.7 and 8.2
GHz and identify a radio core undetected in all previous observations. The SE
hotspot has a higher flux density than the NW one does by a factor of 6,
suggesting that there can be a Doppler boosting effect in the SE one. In this
scenario, we estimate the advance speed of the jet head, ranging from
$\sim$0.1c -- 0.3c, which yields a mildly relativistic case. The projected
linear distance between the two hotspots is $\sim13$ kpc, yielding a linear
size ($\leq20$ kpc) of a Compact-Steep-Spectrum (CSS) source. Combined with new
\black{high-frequency ($\nu_\text{obs}\geq44$ GHz) and archived low-frequency
observations ($\nu_\text{obs}\leq8.2$ GHz)}, we find that injection spectra of
both NW and SE hotspots can be fitted with a continuous injection (CI) model.
Based on the CI model, the synchrotron ages of NW and SE hotspots have an order
of $10^5$ yr, consistent with the order of magnitude $10^3 - 10^5$ yr observed
in CSS sources associated with radio AGNs at an early evolution stage. The CI
model also favors the scenario in which the double hotspots have experienced a
quiescent phase, suggesting that this RLAGN may have transient or intermittent
activities.
