Message "Failed to fetch" when attempting to sync

Happened to 2 of 3 of my android devices. It worked with the 3-year-old. I only received this message with the 7-month and 4-month old devices, one phone and one tablet.

Please help.

Also couldn’t get the wallet working on either device either but, again, it worked with the old one, but I was hoping to sync the wallets anyway.