Gallery with slimbox: where's the caption and navigation arrows (Next and Previous)

I'm using this code to show a gallery with thumbnails. When clicking on a thumbnail, the image popups up in a lightbox (slimbox).

[[Gallery? &plugin=`slimbox` &overlayOpacity=`0` &album=`[[*kiesalbum]]` &toPlaceholder=`gallery` &thumbTpl=`galleryrowTpl2` &thumbWidth=`228` &thumbHeight=`171` &thumbQuality=`80`]]

[[+gallery:notempty=`<div class="row" id="gallery">[[+gallery]]</div>`]]

But it does not show the captions (descriptions of the images). It just says "Image x of x".
The navigation arrows are also missing; clicking on the image just closes the image.

Anyone got a solution?

There might be a solution to the navigation arrows here? https://github.com/modxcms/Gallery/issues/55

Thanks, but I tried that and it did not work.

How come noone ever found a solution or complains on this? Must be more people using the Gallery extra.

Does it work correctly with a different lightbox?

Do you have the necessary jQuery files present and accessible? (Probably not necessary to ask this - but I have made such mistakes in the past!)

Does it make any difference if you call the snippet uncached?

The lightbox itself is working, so everything is in place. Only the caption and navigation are missing. Please read my issue.

BTW: uncaching it makes the entire gallery disappear. That's why I'm using it without the '!'.