Known bug? (accidental collides with clef)

[Michael Meixner]

Hello all,

just stubled over this one - an accidental collides with a clef; 
narrowed it down to this snippet - is this a 
known bug (if not I'll send it to the bug-list) ?

%
% Here's a problem of an accidental colliding with a clef
% (see how the error doesn't happen in the second case:
% obviously it's depending on the rhythm of the other voice,
% too little room after the eigths? ) 
% 

\version "2.9.4"

\score {
        <<
        \new Staff { \relative c'' { e8 e e4 e4 e }}
        
        \new Staff { \relative c' {r4 \clef alto fis4
        \clef treble r4 \clef alto fis }}
        
        >>
} 

\paper { ragged-right = ##t }

% EOF