Hi,
I’ve got exactly the same problem with my mobile native browser (Samsung Edge S7). I found out that changing a couple of CSS parameters makes the header image display correctly. The problem is that I’m no coder, so my solution is just a temporary one and I do hope somebody more expert will fix the issue better.
Basically, this is the code I added in the CSS menu (please change the max-width to fit your tablet):
@media screen and (max-width: 480px) {
.has-header-image .custom-header-media img,
.has-header-video .custom-header-media video,
.has-header-video .custom-header-media iframe {
position: absolute;
height: 100%;
left: 50%;
max-width: 1000%;
min-height: 100%;
min-width: 100%;
min-width: 100vw;
width: auto;
top: 50%;
padding-bottom: 1px;
-ms-transform: translateX(-50%) translateY(-50%);
-moz-transform: translateX(-50%) translateY(-50%);
-webkit-transform: translateX(-50%) translateY(-50%);
transform: translateX(-50%) translateY(-50%);
object-fit: cover;
}
}
Basically, I’ve changed position in “absolute” and height in “100%”. I’ve also added “object-fit: cover”. I hope it’ll work also for you and somebody more familiar than me with coding could give some additional help.