I was taught in school by teachers that in UK, it's pronounced as flahhhhhh.......

but when I went to the UK, they pronounce it as 'flower'.

clearly, Malaysian teachers are not up-to-date!!

the british way is flower. For them, no difference between flour and flower.

well, take it from someone who has lived in the UK.
maybe that was in the past, but my UK friends all pronounce the flower way ....