Hi all,
Thanks for your help.
1. Unfortunately, the Repair Geometry did not help because dangles are probably too large and not actually geometry problem
2. The Planarize is a good start but it only works for simple self-intersection and/or dangle. Anything more complex need a manual fix, as shown below.
3. The Topology rule... I tried to adjust the XY Cluster Tolerance to 0.001 degree to match my self-intersection but I received an unknown error...
This is all I managed to test this week... As the Repair Self Intersection tool in the Topographic Production extension needs extra licensing, I wonder if there would be a similar tool in QGIS (but I am not as experienced in QGIS!)