I think this started when I updated to WordPress 5.7 but I can't be sure. This was 100% working previously.
Basically I have set a border radius on images in this archive list, the first result it shows correctly but the rest don't have the border radius working, so they appear as circles.
There are 2 ways we can fix this temporarily until a permanent fix is provided.
The first method is that you can assign a custom class to the image and then target that custom class with the border radius css, example
.custom-class{
border-radius: 100px !important;
}
Or we can make the css code more specific like below.
.tb-image-dynamic a img{
border-radius: 100px !important;
}
Which will target only the image tag within the anchor tag of the tb-image-dynamic element class.
Please let me know if this provides a temporary workaround. As mentioned this will be fixed in 2-3 weeks when the release is made. Currently the plugin is scheduled to go into Q&A to ensure there are no feature breaking bugs with the new release.