Adding a png image with no background[transparent] always shows border and even after overriding it with CSS it shows very faint border

[kingx619]

The html along with bootstrap I used is

  <img class="img-fluid my-auto" src="images/telogo.png" alt="mylogo">

The output I am getting is

After overriding bootstrap with internal css the border is still prominent..This image worked fine till bootsrap 5.0 beta 3

 <img class="img-fluid my-auto" src="images/telogo.png" alt="mylogo" style="border : none ;">

Visible border even after border removal

Is it a bug or am I making some kind of mistake ??