Why did the dog behave like that, and should I scare it the next time I see it (details inside)

So this is an update to this question since new information has come out and I just had new experience with the dog.

So over time I have learned that the dog is quite infamous in my neighborhood. It usually roams the park at night and will chase anyone coming near the area, so it wasn’t just me. No one has done anything about it, maybe because the owner is also a questionable figure.

So anyway, yesterday I was riding back home from work. I have been taking the alternative road since the incident of the last question, but there is a cross between the old road and the road I was taking. And that was where I was at when the dog ran toward me. I was riding very slowly at the time so I was able to see it coming now, unlike the previous incidents. I decided to stop still in my track and see what would happen, because dogs usually don’t attack people who don’t run. The dog came to me and sniffed my leg. Then it made a strange jump backward then ran away.

Now this is the part where it got strange. I was about to ride off when the dog ran back and start barking while doing that strange jump earlier, then ran away again. I then continued to ride back home. But just as I was close to my door the dog came running again and barked again. This time it just kept on barking and sniffing without running away. I was at a loss of what to do when a group of men saw me and one of them came out to shoo the dog away.

Is anyone here familiar with dog behavior? If so do you have any idea why the dog behaved that way? I learned that dogs don’t attack anyone who stands still calmly, because they aren’t people with any motive who are afraid of being “found out”. But this dog just continued to harass me even after I stopped moving. It’s as if it was trying to start a fight. My friend suggested the possibility of it not being vaccinated for rabies. Is that true?

I’m considering shooing it away the next time I see it like the men did, but I’m also afraid of getting bitten. I’m not sure if it’s just “all bark and no bite” or if it’s really a mentally disturbed dog that will cause harm. What I saw last night is really unusual and I’m really worried. I can take all the alternative routes in the world, but when the dog just came to me right at my door I don’t think I have any choice left. What should I do?

Not sure if it helps, but I was able to get a clear view of the dog. It has the short body similar to a corgi, but its head is that of a German sheperd.