It is recommended to separate the intake of creatine and caffeine if you consume high doses of caffeine (3-5 mg/kg).

noli's read

This recommendation is based on a seminal 1996 study (Vandenberghe et al., RCT), which observed that caffeine appeared to negate the ergogenic effect of creatine on explosive performance, while increasing gastrointestinal side effects. However, subsequent research is far from unanimous. More recent meta-analyses (such as that of Trexler and Smith-Ryan) suggest that the interference could be context-specific or dependent on individual tolerance rather than a universal biological rule. Many studies have failed to reproduce this cancellation effect in trained athletes. It is likely that the interaction is exaggerated in wellness literature, as the massive doses of caffeine used in the initial study do not always reflect actual consumption habits. In summary, although the interaction is plausible at very high doses, it is not consistently observed in common practice.

the sources

1. 1strongerbyscience.com