after searching for months i finally found the culprit, it was this damn addon. it makes firefox so slow that gmail or youtbe hardly work anymore, many other sites don't even load. absolutely NOT recommended if you use firefox.

Works well for me

Extension not working on Android and the developer doesn't reply e-mails.
On Android the automation simply does not work, be it by time or by location.

Extremely poor compared to chrome version. Will overwrite splash screens, not handle div borders (leading to white bars everywhere), works poorly with most websites. Better than nothing, but not saying much.

"thanks for the addon" - my eyes to the dev