Especially between two vowels, the Spanish b/v sound is often pronounced as a voiced bilabial fricative, which is a sound that doesn't exist in most pronunciations of English: https://en.wikipedia.org/wiki/Voiced_bilabial_fricative This can sound to English speakers like either a "b" or a "v" depending on context and expectations of the listener. And the pronunciation itself can vary by region or speaker as to how close it is to an actual English "b" or "v" sound. As far as Spanish speakers who actually make a conscious *distinction* between "b" and "v", they are often TV presenters and other people with media training, possibly influenced by English or other languages or maybe trying to speak that way for the sake of clarity. But the distinction is generally not made naturally among Spanish speakers.

After 5 years of studying Spanish, I don't worry about this anymore. I agree with Armin's answer. It varies from region to region. The only times now that I am aware of it is when a native speaker texts me on the phone, sometimes they will adjust their spelling with "b" or "v" which can be jarring at first. (Theoretically that shouldn't happen, as spelling in Spanish is consistent and easy, but texting has changed how spelling works for some people. Or they were not good spellers to begin with.) But yeah, You will hear some people say "cerVesa" and people from somewhere else may pronounce it more "cerBesa."

I’m a non-native Speaker but I believe it is a matter of different local variations of language. Spanish is spoken over a vast area by a very high number of people and not pronounced likewise by all of them.

While there can be some regional differences in pronunciation because of the influence of local languages, for instance in Mallorca and Valencia, both are pronounced like /b/ in spanish. Spanish "Real Academia" on this: https://www.rae.es/dpd/v (in spanish)

We normally don't make a difference in the pronunciation of b and v