Error with slider during loop -- Trying to use variable slider labels

If this template helps then use it. If not then just delete and start from scratch.

OS: Win10
PsychoPy version (e.g. 1.84.x):
Standard Standalone? yes
What are you trying to achieve?:
I want people to make five different ratings (e.g., curiosity, degree of mystery) for a sentence on-screen.
I am using the slider component to collect the ratings.
The sentence will remain static at the top of the screen.
I want to show one rating question at a time (e.g., How curious are you to learn what happens next, How a great a mystery does this sentence present?).
The question and the anchor will change after each rating.

In summary: People will read a sentence and a press a spacebar when they have understood it. Then they will make five ratings, one-at-a-time, that measure different dimensions about that sentence.

What did you try to make it work?:

I created two routines, one for which people read the sentence and one for which they make their ratings. The sentence reading routine is a straightforward text + keyboard response. The sentence ratings routine has the same sentence in the same location, but adds an additional text component for the rating question and the slider component.

I created a loop around the ratings routine.

I first created a conditions file with two variables, one for the rating question and one for the anchors that will appear. In Labels for the slider component I entered $anchors and received a syntax error (EDIT: I did switch to setEveryRepeat from constant):

I don't know the appropriate default value for a 'labels' parameter. Please email the mailing list about this error
## Running: C:\Users\Zared\Documents\PsychoPy\diss\Pilot V2 Masters\ ##
3300.9054     INFO     Loaded monitor calibration from ['2019_08_08 10:34']
  File "C:\Users\Zared\Documents\PsychoPy\diss\Pilot V2 Masters\", line 112
    labels=[$anchors], ticks=(0,1,2,3,4,5,6),
SyntaxError: invalid syntax

I then tried to separate the anchors into two variables, thus for Labels I entered $leftAnchor, $rightAnchor to no avail and received a similar syntax error pointing at the labels argument. The error message is exactly the same, so I did not include it for brevity.

I realize that I could create 5 different sliders with the same location and trigger them to start and stop using conditions and a code component. (I will probably move forward with this, clunkier solution for the sake of getting data). However, I would prefer the more elegant solution of being able to use variables for the slider Labels. Am I missing something about how to do that correctly?