In this paper, the redshift evolution of the galactic bar properties, like the bar length, pattern speed, and bar fraction, has been investigated for simulated galaxies at stellar masses of M-* > 10(10) M-circle dot in the cosmological magnetohydrodynamical simulation TNG50. We focus on the redshift evolution of the bar pattern speeds and the fast bar tension. We show that the median value of the pattern speed of the bars increases as the redshift grows. On the other hand, although the median value of the bar length increases with time, the ratio between the corotation radius and the bar radius - namely, the R = R-CR/R-bar parameter - increases as well. In other words, the corotation radius increases with a higher rate than the bar length. This directly means that galactic bars slow down with time, or equivalently as the redshift declines. We discuss the possible mechanisms that reduce the pattern speeds in TNG50. We demonstrate that while mergers can have a significant impact on a galaxy's pattern speed, they do not play a crucial role in the overall evolution of mean pattern speed within the redshift range z <= 1.0. Furthermore, we show that the R parameter does not correlate with the gas fraction. Consequently, the existence of gas in TNG50 does not alleviate the fast bar tension. We show that the mean value of the pattern speed, computed for all the galaxies irrespective of their mass, at z = 1.0 is Omega(p) = 70.98 +/- 2.34 km s(-1) kpc(-1) and reduces to Omega(p) = 33.65 +/- 1.07 km s(-1) kpc(-1) at z = 0.0. This is a direct prediction by TNG50 that bars at z = 1.0 rotate faster by a factor of similar to 2 compared to bars at z = 0.0. C1 [Habibi, Asiyeh; Roshan, Mahmood; Abbassi, Shahram] Ferdowsi Univ Mashhad, Fac Sci, Dept Phys, POB 1436, Mashhad, Iran. [Roshan, Mahmood; Hosseinirad, Mohammad; Khosroshahi, Habib] Inst Res Fundamental Sci IPM, Sch Astron, Tehran 193955531, Iran. [Aguerri, J. A. L.] Inst Astrofis Canarias, Calle Via Lactea S-N, Tenerife 38205, Spain. [Aguerri, J. A. L.] Univ La Laguna, Dept Astrofis, Av Astrofisico Francisco Sanchez S-N, San Cristobal la Laguna 38205, Tenerife, Spain. [Cuomo, Virginia] Univ Atacama, Inst Astron & Ciencias Planetarias, Ave Copayapu 485, Copiapo 1350000, Chile. [Abbassi, Shahram] Univ Western Ontario, Dept Phys & Astron, London, ON N6A 3K7, Canada. C3 Ferdowsi University Mashhad; Institute for Research in Fundamental Sciences IPM; Instituto de Astrofisica de Canarias; Universidad de la Laguna; Universidad de Atacama; Western University (University of Western Ontario)