escape code not parsed

Hi!

I have a project  where i am using this library,  even if not directly
because i am using  a lisp wrapper.  I have a  very weird problem with
keyboard input:  I use the key  "down arrow" and "up  arrow" to scroll
the text  inside a window but  sometimes, if i keep  pressing the down
arrow, i  get a sequence  of events "esc  [ B" (three  chars) instead,
this is the sequence  that encode the down arrow as far  as i know. So
is like  the event is not  parsed by the  library. The bug is  more or
less  reproducible but  i  have  no clue  about  what  can cause  this
behaviour, the best resource i have  found that seems related seems to
be that as  i am doing a  fair amount of computation when  no event is
returned (i am using a non blocking input):

https://invisible-island.net/ncurses/hackguide.html#input

"The wgetch()  code distinguishes  between function key  sequences and
the same  sequences typed manually  by doing  a timed wait  after each
input character that could lead a function key sequence. If the entire
sequence  takes  less than  1  second,  it  is  assumed to  have  been
generated by a function key press."

Have someone got a problem like  this before?  Any hint is appreciated
because, as i said, i have no clue.

Thanks in advance.
C.

PS: For reference here you can find the software:

https://notabug.org/cage/tinmop/