I have repeatedly read in this forum that Karna lost in Swayambar and wasn't able to put the string around the bow or something like that. Can someone provide a link to this ?
The one that I read or came across, mentions that Draupadi's remarks on Sutaputra did happen and that he was not allowed to shoot.
https://www.sacred-texts.com/hin/m01/m01190.htm
And that assemblage of monarchs, their hope of obtaining Krishna gone, looked sad and woeful. And beholding the plight of those monarchs, Karna that foremost of all wielders of the bow went to where the bow was, and quickly raising it strung it and placed the arrows on the string. And beholding the son of Surya--Karna of the Suta tribe--like unto fire, or Soma, or Surya himself, resolved to shoot the mark, those foremost of bowmen--the sons of Pandu--regarded the mark as already shot and brought down upon the ground. But seeing Karna, Draupadi loudly said, 'I will not select a Suta for my lord.' Then Karna, laughing in vexation and casting glance at the Sun, threw aside the bow already drawn to a circle.