CSS transition and transform-style not working on mobile - css

Question

I've successfully gotten two images to flip like a card when hovering over. Using transition and transform-style. It works except on mobile (iPhone; chrome and safari). What am I doing wrong? Any guidance very much appreciated.
I've reviewed previous posts on StackOverflow but what I've found did not help my situation.
<div class="flip-box">
<div class="flip-box-inner">
<div class="flip-box-front">
<img src="./resources/images/green.jpg" alt="" style="width:421px;height:552px">
</div>
<div class="flip-box-back">
<img src="./resources/images/brown.jpg" alt="" style="width:421px;height:552px">
</div>
</div>
</div>
.flip-box {
background-color: transparent;
width: 421px;
height: 552px;
border: 0px;
-webkit-perspective: 1000px;
-moz-perspective: 1000px;
-ms-perspective: 1000px;
perspective: 1000px;
}
.flip-box-inner {
position: relative;
width: 100%;
height: 100%;
text-align: center;
transition: transform 0.8s;
-webkit-transform-style: preserve-3d;
-moz-transform-style: preserve-3d;
-ms-transform-style: preserve-3d;
transform-style: preserve-3d;
}
.flip-box:hover .flip-box-inner {
-webkit-transform: rotateY(180deg);
-moz-transform: rotateY(180deg);
-o-transform: rotateY(180deg);
-ms-transform: rotateY(180deg);
transform: rotateY(180deg);
transform-style: preserve-3d;
}
.flip-box-front, .flip-box-back {
position: absolute;
width: 100%;
height: 100%;
backface-visibility: hidden;
-webkit-backface-visibility: hidden;
-moz-backface-visibility: hidden;
-o-backface-visibility: hidden;
-ms-backface-visibility: hidden;
}
.flip-box-front {
transform-style: preserve-3d;
}
.flip-box-back {
-webkit-transform: rotateY(180deg);
-moz-transform: rotateY(180deg);
-o-transform: rotateY(180deg);
-ms-transform: rotateY(180deg);
transform: rotateY(180deg);
transform-style: preserve-3d;
}
I expected the card to flip back and forth on mobile but it only transitions once.

Answer 1

Not answering the direct question, but maybe try the CSS from DavidWalsh.name (with prefixes).
/* entire container, keeps perspective */
.flip-box {
-webkit-perspective: 1000px;
perspective: 1000px;
}
/* flip the pane when hovered */
.flip-box-inner:hover .flipper, .flip-box-inner.hover .flipper {
-webkit-transform: rotateY(180deg);
transform: rotateY(180deg);
}
.flip-box, .flip-box-front, .flip-box-back {
width: 421px;
height: 552px;
}
/* flip speed goes here */
.flip-box-inner {
-webkit-transition: 0.6s;
transition: 0.6s;
-webkit-transform-style: preserve-3d;
transform-style: preserve-3d;
position: relative;
}
/* hide back of pane during swap */
.flip-box-front, .flip-box-back {
-webkit-backface-visibility: hidden;
backface-visibility: hidden;
position: absolute;
top: 0;
left: 0;
}
/* front pane, placed above back */
.flip-box-front {
z-index: 2;
/* for firefox 31 */
-webkit-transform: rotateY(0deg);
transform: rotateY(0deg);
}
/* back, initially hidden pane */
.flip-box-back {
-webkit-transform: rotateY(180deg);
transform: rotateY(180deg);
}