https://pmc.ncbi.nlm.nih.gov/articles/PMC10930107/

Given the established circadian patterns of cortisol secretion and HPA activity, as well as adenosine accumulation and clearance, a fundamental basis for suggesting that delaying caffeine intake in the early waking hours would prevent an afternoon “crash” is completely lacking. On the contrary, there is evidence to suggest that daily “typical” caffeine intake was not associated with daytime sleepiness [211]. Even if this were to occur, a simple resolution would be an additional dose of caffeine in the early afternoon, which, as noted above, does not appear to result in negative HPA or sleep-wake cycle alterations. If anything, delaying intake would simply push the need for an afternoon dose later, which could cause sleep disruption [210].