Front page slider particles and loading

Love this theme. I have two issues that have popped up in recent updates:

1. The particles appear warped on the page, but if you resize the page (e.g. resizing the window, changing zoom, inspecting element), some sort of update triggers and the particles look normal again. How can I make it so that they’re normal from the start?

2. Loading takes a very long time on the main slider, usually 5+ seconds. Do you know what the cause could be, and how we could reduce the loading time?

Thanks in advance for your help!

The page I need help with: [log in to see the link]