Marketo replacing classes on Landing page.
I have a landing page with a Marketo image on it. For some reason Marketo seems to be removing the css class "card-img-top" and replacing it with "lpimg" which is breaking the styles.
On the first two images it is working fine. It's onlly on the last one this is happening. See the gaps at the sides of the third image. 
See below
Template code:
<div class="mktoImg" id="Readmore3Image" mktoName="Third Read more Image">
<img src="https://info.thewebsite.com/rs/911-BEG-887/images/planogram-readmore.png" class="card-img-top" alt="">
</div>
The Code when I preview it:
<div class="mktoImg mktoGen" id="mkto_gen_Readmore3Image"><img src="https://info.thewebsite.com/rs/911-BEG-887/images/Thumb-LP-GalleryCV-300x230.png" class="lpimg" alt="" id="Readmore3Image"></div>
Anyone else experience this?
Thanks,
Gerard
