Fibonacci prefix antipower conjecture

Let $F_n$ be an even Fibonacci number, where the Fibonacci numbers satisfy the usual recurrence, and let $\mathbf{f}$ denote the Fibonacci word. A $k$-antipower is a concatenation of $k$ pairwise distinct blocks of equal length. Fibonacci prefix antipower conjecture. There is an $(F_n-1)$-antipower with block length $\frac{F_n}{2}+F_{n-1}$ that is a prefix of $\mathbf{f}$. Based on the supplied text, this is an empirical conjecture about explicit antipower prefixes of the Fibonacci word; no resolution is given.