Pitch detection algorithms "give up" after very little
You might just have the magnitude or gain on your test input signals turned down too low.  Or the threshold set too high.  Or poor microphone placement.  Or perhaps you need an AGC controlled gain block before the pitch estimation algorithms to stabilize the decay portion of any ADSR-"like" amplitude envelopes or sound evolutions.

The above assumes you have a decent S/N ratio (e.g. little background noise and no harmony or accompaniment).

Also, you use a singular "best algorithm", when multiple algorithms (plural) may more appropriate for different portions of a note's envelope, and/or different sized stringed instruments.  In addition, your list of algorithms does not include any of the newer machine learning (ML or Convolutional DNN) inference methods of pitch detection/estimation or octave resolution.  Perhaps even RNNs to use melodic history to improve prediction statistics.