Does anyone know what causes Sync to fail in Firefox? I’m signed in on two devices with 6 to 9 tabs max open. My tabs don’t sync or send from one device to another properly. My history also doesn’t work. I just visited a site 2 minutes ago and all I see in my history is sites I visited 12 hours ago. I’m at my wits’ end and ready to find another browser. Please help if possible.