I also had issues with the Sylvania plugs being very unreliable. They sell 2 versions that are nearly identical except the Ledvance version seems much more reliable on my mesh.
I added some Tradfri repeaters to strengthen my zigbee mesh and that seems to have helped with the Osram version, but I think I'm down to only 2 of them, on the periphery of my mesh. If I ever make it back to Ikea they'll be gone. 
Download the Hubitat app
