When jQuery or lazy loading images is also loaded by other plugins and themes, conflicts can arise. First step is always to disable all other plugins and revert to a default theme. If FPD works as expected, which it should, then you can start to introduce your other plugins one by one and then swap the theme back to find the issue.
In most circumstances you can try FPD in no conflict mode - Settings > Advanced > Troubleshooting > JQuery No Conflict Mode - on.
If your theme has jQuery options in it's settings you can also go through them to find the best combination.
Products not loading usually means your theme or another plugin is using Lazy Load Images as well as FPD using it. Try turning it off in FPD. Settings > Advanced > Miscellaneous > Lazy Load > Off.