  Our previous studies [J. Phys. B 53, 125101 (2020); Euro. Phys. J. D 74, 191
(2020)] have predicted that the atom-fullerene hybrid photoionization
properties for X = Cl, Br and I endohedrally confined in C60 are different
before and after an electron transfers from C60 to the halogen. It was further
found as a rule that the ionization dynamics is insensitive to the C60 level
the electron originates from to produce X-@C60+. In the current study, we
report an exception to this rule in F@C60. It is found that when the electron
vacancy is situated in the C60 level that participates in the hybridization in
F-@C60+, the mixing becomes dramatically large leading to strong modifications
in the photoionization of the hybrid levels. But when the vacancy is at any
other pure level of C60, the level-invariance is retained showing weak
hybridization. Even though this case of F@C60 is an anomaly in the halogen@C60
series, the phenomenon can be more general and can occur with compounds of
other atoms caged in a variety of fullerenes. In addition, possible
experimental studies are suggested to benchmark the present results.
