  Tidal orbital decay plays a vital role in the evolution of hot Jupiter
systems. As of now, this was only observationally confirmed for the WASP-12
system. There are a few other candidates, including WASP-4 b, but no conclusive
result could be obtained for these systems as of yet. In this study, we present
an analysis of new TESS data of WASP-4 b together with archival data, taking
the light-time effect (LTE), induced by the second planetary companion, into
account as well. We make use of three different Markov-Chain-Monte-Carlo
models; a circular orbit with a constant orbital period, a circular orbit with
a decaying orbit, and an elliptical orbit with apsidal precession. This
analysis is repeated for four cases. The first case features no LTE correction,
with the remaining three cases featuring three different timing correction
approaches. Comparison of these models yields no conclusive answer to the cause
of WASP-4\,b's apparent transit timing variations. A broad range of values of
the orbital decay and apsidal precession parameters are possible, depending on
the LTE correction. This work highlights the importance of continued
photometric and spectroscopic monitoring of hot Jupiters.
