I agree it feels really bad because before. once you found the signal.. you would ping it and it would not have a chance to expire.
now there is so much waiting involved that you find the signal. and halfway trough setting up your triangle it will expire right in front of you.
repeat 1-2x until you get lucky enough.
it just feels bad. though the triangulation minigame in itself is not the problem and i quite like it. the signals should not be allowed to expire if its within your FOV f.ex.