12 April's new daily confirmed cases for UK seem to be dramatically different:
ECDC says 8719 (https://ourworldindata.org/grapher/daily-cases-covid-19?country=GBR), while
PHE says 84279-78991=5288 (https://en.wikipedia.org/wiki/2020_coronavirus_pandemic_in_the_United_Kingdom#Timeline).
Now, I know that there could be something different in the definition of "new cases" or in the way they are measured. What is exactly the difference due to?
Also, ECDC's data is quite alarming because it's a dramatic jump looking at ECDC's same data for the past days: should I be worried?