When I share a website on mobile, usually my other linked device will appear under "Send to device" in the Share menu, and I'm able to send the tab to that device with no issue. However, sometimes when I try to do this, my linked device will NOT show up; I will only see a circle with a plus sign that says "Add new device." This can happen even if the linked device is turned on and recently synced to FF (but it shouldn't matter, as I can usually send a tab to a device even if that device is not currently on). I have tried the following troubleshooting, but none of them work: pressing Sync Now in my FF Android account settings, refreshing Synced Tabs, closing the app and clearing the cache. Eventually, I'll try again and find that my linked device is once again visible under "Send to device," but I have no idea what makes it work or break.

Does anyone else experience this and/or know why it happens and how to fix it?