Things look a bit worrying if the polls are correct:
Five polls in a row with a No lead but, two years before the 1st Referendum, support was only around 30% and then surged to 45% by the day.
Why did that happen?
Researchers at LSE, reported this in 2016:
I explored this question in the context of the referendum for the independence of Scotland. Results based on experimental and survey data show that pro and anti-independence arguments did influence voting decisions in the campaign for the Scottish referendum, but this effect crucially depended on two elements: the share of undecided voters, and the imbalance between a riskier “yes” for independence and a safer “no” for remaining in the UK. The combination of these factors led to a one-sided persuasion effect of information, meaning that only support for independence significantly increased after exposure to a mixed set of arguments.https://blogs.lse.ac.uk/politicsandpolicy/does-campaign-information-actually-change-voters-minds/