Before looking at the video, just your description make me think you are crossing over with the ground somewhere.
If this is an older bike, the problem may be the way the turn indicator lamp is powered.
Yamaha put the indicator lamp across the hot wires going to the turn lights figuring the voltage drop across it would keep the off side lights from glowing while using them as ground for the lamp. With LEDs the power required to light them up will easily flow thru the whole circuit lighting up everything.
To test for the old wiring condition, pull the indicator lamp from the dash and see if the signals work properly.