Hi, Vincent Mross
Have you tried making product cache?
If not please make product cache from sellacious backend.
Follow this documentation https://www.sellacious.com/documentation-v2#/learn/how-to/how-to-rebuilt-cache
I'm unable to download the file.
Kindly reach me on live chat support and i will look into the issue.
Error: Call to undefined method SellaciousCacheCli::setHeader(): Call to undefined method SellaciousCacheCli::getClientId()
Php executable cli is not enable on your server, kindly ask your server provider to to so.
Once enabled your will not get error in cache log