Some background and a brief history of the dimmer, before answering the question. In 1959 Lutron invented the dimmer and brought the world the ability to control the level of their light. In 1975, X10 created the first communicating protocol for dimmer creating the ‘smart dimmer’. Phillips created the first LED bulb that replaced the incandescent bulb in 2009.
Smart dimmers allows the user to change the light level remotely and/or through automation systems. When traditional dimmers turn off they remove all electricity from the bulb and the bulb is off. Smart dimmers allow a small trickle of electricity to flow though the bulb when turned off. This small trickle of electricity powers the communication electronics inside the dimmer. This flow of electricity was small enough that the incandescent bulb did not emit any light. X10 designed the circuits this way to accommodate the majority of homes built in the world.
This trickle of electricity is the source of the problem – Why your (LED) bulbs glow when the dimmer turns off. LED bulbs need 1/10 of the electricity to produce the same light as an Incandescent bulb. Now his trickle of light flowing through the bulb is enough to create a glow in the bulb. This savings benefit is also a problem for homeowners with smart dimmers. This glow is most noticeable in circuits that only have 1 bulb. The more bulbs on the circuit the glow is dimmer or no glow at all.
The home automation manufacturers are working on the problem. They have developed dimmers the have a lower minimum wattage by reducing the amount of electricity needed to operate the electronics. If you have a newer home utilizing the neutral wire will help. In rooms were dimming is not needed, swapping to a smart switch will also remove the glow. The final option is to live with it. For example my bathroom lights glow ever so faintly, but the benefit of automated lights outweigh the tiny glow they emit.