At 2:40 in your video the Y carriage snaps as one of the stepper motors skips a step - this is likely either caused by the leadscrew pitch mismatch between the 2 Y linear rails from a known manufacturing QA/QC issue, or possibly some other reasons discussed in here and elsewhere: "Bump" in Y-axis
Easiest fix will likely be find a pair of linear modules with the same travel and pair them together.
Glad you’re able to get it running! Ask around if you run into issues, lots of people on here that are knowledgeable in getting the most out of this machine!