LED GU10 lights come on randomly
I'm assuming your dimmer is rated for LED, ideally with a neutral wire?  LED dimming is a morass of conflicting quasi-standards, and a lot of LED makers cut shortcuts by calling themselves "dimming" but only working with certain modern dimming methods. 

Old style dimmers are made for incandescent only - they don't have a neutral wire, and power themselves by flowing a small amount of current through the circuit at all times.  Incandescents don't care (the current is too little to make them light up). But for LEDs, what happens really depends on how well the LED is engineered for working in old-style dimmers. 

And LEDs do list the types of dimmers they're compatible with, on their data sheet. 

But beware Feit Electric, Lights of America, or Utilitech.  Those are "bottom shelf" duff brands made to hit a price-point.  Here's the problem with that: The LED emitters are solid.  But they require an electronic driver circuit to translate 120V into constant-current to drive the LED.  When they must shave costs to hit their price-point, there are many ways to cut corners on that driver circuit, and most of them add up to dramatically shorter life, for instance by using cheap electrolytic capacitors.  Also, they cut functions like the ability to "dim" well. 

Done properly, LEDs are a 30 year bulb. I've never had an LED fail except for a Lights of America.  I also have 18 years of experience with CFLs and yeah, only the bottom shelf ones fail there too. I get 10 years of service out of the others. 

Try brands like Cree, GE, Philips, Sylvania.  They're not much more expensive if you shop around.