I did this (tightened it just a tiny bit) last night before sleeping, and it made things worse. Then I went back to your previous post:
I turned back clockwise a bit (loosened it slightly), and voila, I found the sweet spot. No more leaks. To be sure, I waited until today morning. Toilet is back to being done dry, no reflective sign of water anywhere on the tiles and grout. I sat there for 5 minutes just to make sure there is no slow-forming droplet leaking out - there is none!

So problem solved!

PS: Screw the bloody technician for playing with the stopcock and then refusing to come back to my unit to right the issue.