Resolved: Changing 1 value of an arrays makes the other values null

override fun onOptionTextChanged(position: Int, text: String) {
   val oldOptions = questions[holder.adapterPosition].options.copyOf()
   Log.d(TAG, "onOptionTextChanged: oldOptions: ${oldOptions.contentToString()}")
   questions[holder.adapterPosition].options = arrayOfNulls(questionOptionAddList.size)
   for (oldDataIndex in oldOptions.indices){
      questions[holder.adapterPosition].options[oldDataIndex]?.text = oldOptions[oldDataIndex]!!.text
   }
   questions[holder.adapterPosition].options[position] = QuestionOptionAdd(text = text)
   Log.d(TAG, "onOptionTextChanged: newOptions: ${questions[holder.adapterPosition].options.contentToString()}")
}

D/AddFormQuestionsAdapter: onOptionTextChanged: oldOptions: []
D/AddFormQuestionsAdapter: onOptionTextChanged: newOptions: [QuestionOptionAdd(text=n, hasImage=false, imageUrl=), null]
D/AddFormQuestionsAdapter: onOptionTextChanged: oldOptions: [QuestionOptionAdd(text=n, hasImage=false, imageUrl=), null]
D/AddFormQuestionsAdapter: onOptionTextChanged: newOptions: [QuestionOptionAdd(text=no, hasImage=false, imageUrl=), null]

// from here, I started to write in the other edit text

D/AddFormQuestionsAdapter: onOptionTextChanged: oldOptions: [QuestionOptionAdd(text=no, hasImage=false, imageUrl=), null]
D/AddFormQuestionsAdapter: onOptionTextChanged: newOptions: [null, QuestionOptionAdd(text=y, hasImage=false, imageUrl=)]
D/AddFormQuestionsAdapter: onOptionTextChanged: oldOptions: [null, QuestionOptionAdd(text=y, hasImage=false, imageUrl=)]
D/AddFormQuestionsAdapter: onOptionTextChanged: newOptions: [null, QuestionOptionAdd(text=ye, hasImage=false, imageUrl=)]
D/AddFormQuestionsAdapter: onOptionTextChanged: oldOptions: [null, QuestionOptionAdd(text=ye, hasImage=false, imageUrl=)]
D/AddFormQuestionsAdapter: onOptionTextChanged: newOptions: [null, QuestionOptionAdd(text=yes, hasImage=false, imageUrl=)]

// from here, I started to write in the other edit text

D/AddFormQuestionsAdapter: onOptionTextChanged: oldOptions: [null, QuestionOptionAdd(text=yes, hasImage=false, imageUrl=)]
D/AddFormQuestionsAdapter: onOptionTextChanged: newOptions: [QuestionOptionAdd(text=no , hasImage=false, imageUrl=), null]

// I'm pulling this out so it's not constantly repeated, it's just easier to read!
val question = questions[holder.adapterPosition]

// wipe all the options to null
question.options = arrayOfNulls(questionOptionAddList.size)
// iterate over all the old options you copied
for (oldDataIndex in oldOptions.indices){
    // copy the text to the option in the same position, unless it's null -
    // they're all null though, you just set it to a null array, so this does nothing!
    question.options[oldDataIndex]?.text = oldOptions[oldDataIndex]!!.text
}
// create a new item at the position you're editing - so you end up with one item
// in an array of nulls
question.options[position] = QuestionOptionAdd(text = text)

override fun onOptionTextChanged(position: Int, text: String) {
    // grab the current data, or create (and add) a new one if it's null
    val options = questions[holder.adapterPosition].options
    val questionOption = options[position]
        ?: QuestionOptionAdd().also { options[position] = it }
    // set the text on the object
    questionOption.text = text
}