Not at all; my 4.4% figure was from the 2011 census data; I doubt there's a more reputable source than that, given that the census data for 2021 isn't released yet.

But, having reviewed it again, it's quoted in many places as 4.4% but according to the Office of National Statistics themselves, it was 4.8% in 2011.

Granted that data is old, but the Office of National Statistics released estimate data in 2018 putting the percentage at around 5.1%

Roblee's source isn't an official source of data like mine is, and estimates a 1.2% rise from 2018 to 2021 when there was only a 0.3% rise between 2011 to 2018, so it seems a little inflated to me. Given it's an unofficial source, I'm not sure how much weight can be given to it either.

Funny how you've accepted Roblee's figures as accurate but assumed mine aren't, isn't it?

Census: https://www.ons.gov.uk/peoplepopulationandcommunity/culturalidentity/religion/articles/religioninenglandandwales2011/2012-12-11
ONS estimate: https://www.ons.gov.uk/aboutus/transparencyandgovernance/freedomofinformationfoi/muslimpopulationintheuk/