@chandrakant.bagewadi,
I used adobe acrobat pro 2020. and the font of the section you are looking for is not even Arial. It is Calibri. Only Page 2 is on Arial

I would suggest you use acrobat reader to inspect a document instead of a web tool. They can be buggy sometimes.
Also, I run the following code:
private void Logic()
{
Document doc = new Document($"{PartialPath}_input.pdf");
foreach (var page in doc.Pages)
{
var jpegDevice = new JpegDevice(new Resolution(120));
// Convert a particular page and save the image to stream
jpegDevice.Process(page, $"{PartialPath}_page{page.Number}_output.jpg");
}
}
I can see the font being bolded, compared to the rest of the words. The JPG file is on the left side, and on the right is Acrobat Reader.
Maybe if you increase the quality will be better.
If this is still not what you want, I can create a ticket for the dev team. Let me know, and I will do that.

Page one and Two
ConvertPdfToJpg_3_page1_output.jpg (171.8 KB)
ConvertPdfToJpg_3_page2_output.jpg (99.5 KB)