Yes, once the conductivity drops below 50µS/cm problems can be introduced.

Standard pH electrodes contain 3.5M KCl as a reference gel. Samples like DI water and other low ionic solution contain very small amounts of salt. These solutions try to leach ions from the reference gel to raise their conductivity levels. This results in very slow, sluggish, and unstable readings from a conventional pH electrode.

Once you go below this value we recommend using an electrode suitable for Low Ionic strength water and Low Ionic strength buffer solutions.