No U-Turn On Quirino Ave?

https://maps.app.goo.gl/rZfHgBvgnHkw6hd39

Long-time driver, mostly overseas. I only drive in Manila when I visit every few years.

This evening, coming from San Marcelino St., I made a left turn when I should have made a right on Quirino Ave.

I had to make a u-turn, so I kept driving until I saw a place where I could. I did not see any No U-Turn signs and the intersection was free, although traffic was at a standstill. I got pulled over by a traffic enforcer because he said it was illegal to make a u-turn there.

Again, I did not see any No U-Turn signs. The traffice enforcer said that even though that was the case, it is still illegal because of the flow of traffic. Is there anything on here that should have told me it was an illegal turn?

Genuinely asking. Not trying to argue.