Menu loses child selections

I am using your cache plugin with my site which uses DIVI and WooCommerce. My menu system has parent – child selections. I can clear the cache and the menu will appear properly but after a few minutes I lose all the child selections. I have tried with minify off and gzip off but doesn’t seem to help. I like your plug in but this is a real problem. Any help appreciated. My site is wwww.alottalabels.com and the menu option that gets affected is “OnLine Store”.
Thanks,
Frank