Why are white men reluctant to approach black women?

I am a black woman, in my mid 20s; I have lived most of my adult life in England. I just find it a bit strange that when a white man finds me attractive and I also find him to be attractive, he will not approach me or even at least say hi. With Asian men or black men I have had similar experiences, but also had the flip side of the situation, where they have approached me. Whereas with white men I can only count on one hand the amount of white men that have come up to me, given the majority of men in England are white.  Is this not strange?

Let me give an example. I saw this guy at my university. When we first fisted our eyes on each other you would tell and feel the chemistry. It was amazing. He is very attractive, dark hair, nice eyes, nice height (am short), well dress, nice physic. You could also tell that he found me attractive, when we made eye contact it was intense, we were in a lift with a lot of people but it just felt like it was me and him. When I looked away, then looked back he was looking at me. Based on this strong connection I assumed he would say something, but it never happened. I have traditional values, so I am not a kind of person who would pursue a man; I like a man to lead. So in that moment I took actions into my hands and said something to see whether he would take the conversation further. I was going for a lecture and genuinely wanted to know what time it was, so I asked him. He replied and we both went our separate ways. After that, I then thought maybe he was not attracted to me or I did something that turned him off. Told myself, his loss and forgot about it as you usually do. But then I saw him other day, we exchanged glances, yet again you could feel the physical chemistry. But again he didn’t say anything. Every time we saw each other it was evident there was an attraction. But he did not make an attempt to take it further than the attraction that was there. Don’t get me wrong I don’t think physical attraction is enough for any form of a romantic relationship but it is a door to get to know somebody further. How would you know if you have things in common with somebody if you don’t speak to them? To me it is just a bit strange, he seemed to be so attracted to me, yet even though he had so many opportunities to approach me, he never did. Let me take another example, same scenario, but in this case the guy was black. One day this guy came up to me and said hi, even though we did not take the conversation further at least he acted upon his feelings. For whatever reason he never approached me, to me it seems as if British white men are reluctant to approach black women. I have had countless similar experiences with British white men.  Is this just me or does this happen to other black women? And if so why are white British men reluctant to approach black women?

*I would like to get a bit of insight into why this is the case, especially from British white men.