How people update their beliefs when faced with new information is integral to everyday life. A sizeable body of literature suggests that people's belief updating is optimistically biased, such that their beliefs are updated more in response to good news than bad news. However, recent research demonstrates that findings previously interpreted as evidence of optimistic belief updating may be the result of flaws in experimental design, rather than motivated reasoning. In light of this controversy, we conduct three pre-registered variations of the standard belief updating paradigm (combined N = 300) in which we test for asymmetric belief updating with neutral, non-valenced stimuli using analytic approaches found in previous research. We find evidence of seemingly biased belief updating with neutral stimuli — results that cannot be attributed to a motivational, valence-based, optimism account — and further show that there is uninterpretable variability across samples and analytic techniques. Jointly, these results serve to highlight the methodological flaws in current optimistic belief updating research.