1 out of 6 Counterbalance Sequences does not work: ReferenceError: 'variable' is not defined

I’ve been trying to counterbalance my experiment (based on Blocks of trials and counterbalancing — PsychoPy v2020.2) and i came across a very peculiar issue:

First of all, running the entire task offline runs smoothly without any hiccups, the only issue is when running online on Pavlovia

I have 6 counterbalance sequences:

I noticed that ONLY when i run a pilot test using CAB, i will receive an error at the beginning of the counterbalance blocks. The error is

ReferenceError: thisL1Instruct is not defined

For the rest of the other sequences, I was able to reached the end of my experiment without any further errors popping up.

Does anyone know what is causing this error? And how i can resolve this?

Any help is much appreciated!

Thank you!

URL of experiment: https://gitlab.pavlovia.org/john_nathan23/modified-flanker-task