I just moved to an apartment close to down-town and despite being a brand new complex, it seems like the bathroom has plumbing issues. All day long there is a very strong and persistent smell of fermented urine that could wake the dead coming from either the sink or the wall column just next to it (which might contain the sewage pipe).
I've poured bleach in the sink and the window stays open but that doesn't help. I stay on a high floor and despite having only 5 more floors above me, it still smells like the pee and poop of a billion people.

Have you come across this situation? Apart from going back to my previous place or changing apartment, are there any permanent or long-term solutions to this? I don't want to be tested positive for jenkem.

This happened all the time when I lived in Hebei..

After calling my landlord, you know what he said? 'it's a toilet! it's supposed to smell'
...
Go figure.
Needless to say, it never got fixed.

Mine isn't supposed to. My poop smells like lavender!

It is the plumbing in the building. You can't control that.
We had a similar problem in shanghai with one of the neighbors keeping a dog on the balcony and pushing the dog poop down the drains. It might also be a neighbor peeing in the sink to save water. You can't control others in the building either.
I would move. Put it down to experience and next time check for smell before renting a place.

try burning incense. keep the holder in the bathroom and light up a stick every time you pop in for a poop or to freshen your nose.

ok if it is the sink, or the toilet there is nothing you can do, but it most likely comes out of the sewage, which wasn't installed correctly obviously, it should have been installed through a different pipe, so the smell of your neighbors would never come through, but if you have signed a long lease already you might want to get someone to change the pipe, it could cost you a bit, or block the sewage with something when you are not using it, and let it open when you do, it should block the smell.

If the stench source is the sink, replace the plumbing with a water trap - an S or U tube. The water trap prevents odors from backing out of the sink. Most Chinese plumbers use straight-thru tubing - hence any and or all odors magically rise through the untrapped drain(s) - Boyle's Law I think (gas expansion).

Thank you. I got some incense to burn for them moment and will see with the landlord if it's possible to change the pipes/tubes

I would try the longer term fixes mentioned above or just move if possible. If you can't, you could just try blocking the sink or wrapping the column with plastic wrap. Cover or seal any areas under the sink and all along that column too.

I had a small amount of smell coming from a bath drain. All I did was simply move the plunger over it when not taking a shower. This simple trick pretty much eliminated my odor problem. Though my smell was very tiny compared to your problem.

I would try the longer term fixes mentioned above or just move if possible. If you can't, you could just try blocking the sink and wrapping the column with plastic wrap. Cover or seal any areas under the sink and all along that column too. Only unblock the sink when you have to use it.

I had a small amount of smell coming from a bath drain. All I did was simply move the plunger over it when not taking a shower. This simple trick pretty much eliminated my odor problem. Though my smell was very tiny compared to your problem.

Also, C4 and Walmart sells hand sized bags of activated charcoal. But not sure how many you would need to absorb strong smells. And they don't work instantly, more like over weeks. They also sell hang up air freshners and fragant wood rounds that do smell nice for a while. Try both if you're looking for any kind of help.