Hello,
I do not see screenshots. Please provide links of them.
1) I’ve checked your site on Samsung mobile, Chrome browser and do not see the Ajax error. What device and browser do you use? What exactly should be done to see the error?
Do you use 5.1.6.1 version of XStore theme?
Try to disable 3rd party plugins, clear cache and check how it works then.
2) Add this code in Theme Options > Custom CSS > Custom CSS for mobile:
.categories-lists-grid .category-list-item-wrapper {
width: 50% !important;
}
.categories-lists-grid.categories-columns-5 .category-list-item-wrapper:nth-child(5n+1) {
clear: none;
}
.categories-lists-grid.categories-columns-5 .category-list-item-wrapper:nth-child(2n+1) {
clear: both;
}
do not forget to clear cache before checking the result.
Regards