PureChat suddenly stopped working during domain transfer

Hi everyone,

I'm using PureChat for the live chat on my website. It worked perfectly fine during the development of the website but now, while I'm transferring my domain to Squarespace, it's all of a sudden broken! Opens a weird window instead of a slide-in and doesn't even work. I've tried removing and re-inserting the code, but nothing helps. Any idea what it can be?

Thanks