I saw this thread when it was first posted - sorry for my late response. I have found that Convertio often does not do a good job of converting from dxf to svg. Here is an example. I have converted the original dxf file with both LightBurn and CorelDraw and opened with Inkscape and they look fine. Lastly I have converted the same original dxf file to svg format using Convertio and it has problems - as shown in the last image below.
My best advise is to purchase LightBurn for $65 (perpetual license) and use it for these conversions. LightBurn also has many other useful tools and features such as auto-trace, node edit, convert to dxf, etc. I would recommend downloading the free trial version to try it out.
David
https://lightburnsoftware.com/pages/tri ... re-you-buy
Convertio 1.jpg
Convertio 2.jpg
Convertio 3.jpg
Convertio 4 - BOE converted with LightBurn and opened with Inkscape.jpg
Convertio 4 - BOE converted with CorelDraw and opened with Inkscape.jpg
Convertio 4 - BOE converted with Convertio and opened with Inkscape.jpg