If you change any of your turn signal bulbs to LED, you remove the load that the flasher needs to have the correct rate. The easy (and less correct) way is to add a ‘load equalizer’. This is nothing more than ceramic resistors. They create heat and have to be mounted away from plastic.
Our LED flasher is self regulating with it’s onboard SMD logic circuit. It’s DOT approved and rated at 20 amps so you can continue to use regular bulbs too.