dotted lines turn solid in pdf conversion

[kleanthis_kalfas]

first of all thanks to anyone who answered. 

so I have made a floor plan in AutoCAD 2021 student version and that includes both solid lines and dashed. 

the problem that I'm facing has to do with the dashed ones . in the model space they appear fine, exactly how I want them to look and so they do to the layout where I have set up sheep ready for printing and even there the dashed are looking fine BUT when I convert the file to a pdf the dotted lines turn solid. 

is there any way I can fix that or a "proper" way to convert a DWG to a PDF cause I'm using an online converter and I'm not sure if that has anything to do with it? 

I'm attaching screenshots of the plan in model space, layout, and pdf 

thanks 

[imadHabash]

Hi,

>> .... cause I'm using an online converter and I'm not sure if that has anything to do with it? 

try from PLOT command to make your pdf files . select AutoCAD PDF plotter .