If you want to remove all cues in Serato, you will run into a problem: Lexicon has a safeguard to prevent exactly that from happening accidentally. Sometimes users add their tracks directly into Lexicon so they don't have any cues, then they sync to Serato which removes all their cues. For that reason, there is a safeguard preventing that.
If you just want to start over with your cues, just set them in Lexicon. Once your tracks have one or more cues, the sync will work as expected.
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