Issues with PCB exports to Gerber and no/incorrect trace width
According to you explication, there are &quot;zero width&quot; items in your Gerber file.  So they are either 0 width or the start point is the same or too near to the end point.
You could check the Gerber files by opening them in a text editor.
You can first look for the Aperture definitions - you can consider this as the &quot;pen&quot; types.
Example
G04 APERTURE LIST*
%ADD10C,0.100000*%
%ADD14R,0.600000X2.200000*%
G04 APERTURE END LIST*

The above define aperture 10 as a circle of 0.1 and aperture 12 as a rectangle with the given X and Y sizes.
You can then look for places where these are used in your file:
D10*

Indicates that the aperture 10 is used for the next lines.
If you have small apertures (0 or much smaller than 0), then you could modify the Gerber file to change the aperture size.  Then load the modified Gerber file and the items that were &quot;too small&quot; should now be too big.
I do not have a good suggestion for items that are &quot;too short&quot;.
Personally, to make sure that the PCBs can be produced by most PCB manufacturers, I use the online Eurocircuits PCB verification tool.  It checks more stuff than my free CAD tool and it is practical in use.
I avoid that the assembly house tells me that the PCB does not match the PCB's manufacturer requirements.