Photos on mobile website blurry and zoomed in?

I’m getting extremely frustrated with trying to create my wedding website on this platform.

Unfortunately my fiancé and I paid for our domain name and it’s printed on our details card, so we are stuck using WeddingWire for our website. I sent an email requesting to forward our domain name, but after searching the forums on here I realize they likely won’t do that.
So I’m trying to make it work, but it’s not going well!
I am using photos from my engagement photoshoot for the website, and they are high resolution photos that look great on my phone. When I transfer them to the website though, they look very blurry and zoomed in even though I resize the images exactly to the specifications that the website is asking for. When I upload the pictures to my website on my computer, The picture quality is great. The mobile preview that shows up on my computer also looks great. When I go on my actual phone though, the mobile version of my website does not look like the preview that was shown on the computer. The pictures get zoomed in and they are bad quality. I have no idea how to fix this, and it is extremely frustrating. I’ve tried all kinds of different photos and they all come out blurry and zoomed in inappropriately. I figured out how to fix the zoomed in issue, but the quality still remains poor. It seems like the issue is only with the photos that are integrated in the design. When I upload pictures separately, like on our photos tab or just as a blog post on the website, the pictures look fine for the most part.
I just don’t know what to do because I can’t get the website pictures looking how I want them, and I don’t really want my guest to go on our website and see bad quality images. I’m very disappointed that we paid to have a domain name that we probably can’t transfer and now we are having issues with the website. If anyone has had issues like this and has been able to fix them, please let me know! I’m going to try to contact customer service if they will allow me to transfer the domain name, but given that I’ve seen other people have had this issue and it wasn’t fixed, I’m not super hopeful.