Kicad6 track widths does not follow Netlist

Hi all,
I’m really engjoying Kicad 6, but tonight I hit a full roadblock. I don’t have a single Net Class defined that has a 0.2mm track width and despite this, K6 insists on drawing all my tracks at 0.2mm width?

I’m trying to do layout of a 14x14 pin BGA chip. Each ball is 0.4mm it is 0.8mm between the center of each ball. I’ve set all my nets to use the BGA Net Class that is defined with 0.155mm track width and 0.1mm clearance. No net is set to use 0.2mm, but K6 insists to start drawing using 0.2mm tracks. Under this BGA, that is just too wide and there is no way I can finish this layout until I solve this.

K6 is apparently aware that the Net Class for each Net should be 0.155mm since I can manually select the 0.2mm track, right click to open Properties and tell it to use the Net Class. It does however go straight back to drawing 0.2mm tracks if I try to draw more. This happens even if I set the toolbar (see enclosed img) to “Track: use netclass width” or if I try to force drawing with “Track: 0.155mm”. Both will draw tracks that are 0.2mm and won’t fit.

I feel like I’m doing something very basic wrong here as this has worked great in 5.99 Nightly and K5. What am I missing?

I’m using K6.0.4-0 on MacOS 11.6.

My only manually defined track width and dimensions:
Screenshot 2022-05-02 at 21.50.00

These are my defined classes. Apart from Power nets, all other nets are assigned the BGA class:

This is what happens when I try to draw. Every single track becomes 0.2mm…

File–>Board-Setup–>Constraints–>Copper–>minimum track width → 0.2mm ??

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Brilliant! I did indeed miss something very basic :slight_smile:
Thanks @mf_ibfeew !

The easiest way to debug stuff like this is to select the track segment and select “Constraints Resolution…” from the “Inspect” menu.

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