I tried to use "Send tab to device" function between my Windows and Android phone. When I sent a tab from android device to PC, the new tab opened on PC immediately. But if I tried to send a tab from PC to android device, I couldn't get notification on my phone. New tabs ONLY appears when I tapped the "sync now" button mannually(see following picture), in fact I saw my account synced automatically on android every few minutes without any issue. I use Firefox international account in China, the synchronization process is a bit slow, but it still works fine, so I don't why this "send tab to android device" function doesn't work normally? ''Note:Most of the time, I use cellular network on my phone.''