custom layout modes implemented by having /etc/mobile/groups/beacon and
also grid.less file overridden to support different layout ( small,
medium, large, xl, xxl, xxxl ) as per requirement. Whenever a page seen
by selecting layout option , .beacon selector will be added by AEM. I do
not see above issue for pages created with page templates but I do see
500 issue for experience fragment pages. I feel like this is a bug in
AEM.