message: Added a comment describes the solution why what a cases we might have there
diff: @@ -604,6 +604,12 @@ export class PriceScale {
  const firstValueIsNull = this.firstValue() === null;
  // do not recalculate marks if firstValueIsNull is true because in this case we'll always get empty result
  + // this could happen in case when a series had some data and then you set empty data to it (in a simplified case)
  + // we could display an empty price scale, but this is not good from UX
  + // so in this case we need to keep an previous marks to display them on the scale
  + // as one of possible examples for this situation could be the following:
  + // let's say you have a study/indicator attached to a price scale and then you decide to stop it, i.e. remove its data because of its visibility
  + // a user will see the previous marks on the scale until you turn on your study back or remove it from the chart completely
  if (this._marksCache !== null && (firstValueIsNull || this._marksCache.firstValueIsNull === firstValueIsNull)) {
  return this._marksCache.marks;
  }
  