Also, I power the uC from USB. I need to put a 0.1 uF in parallel to Vcc and Gnd.
Put a 4u7 electrolit capacitor at USB Vcc and Gnd if you supply your uc with USB bus not 0.1uf.
So, I’ve added a 500 k resistance between ground and D-. And it works!!
That's very strange to do, you didn't have to do that. You'll get another issue if you use different cable length, like more than 5 meters.
You must be had hardware wiring issue, the circuit was not that critical as long as enough ground plane or ground wiring and also a stable supply.
I tested my circuit with breadboard (which don't have ground plane) and nothing happen like that even I use long enough cable for testing. and I tested at many AVR type for my projects.
Here, I was just able to get 3.6 V, 1 Watt zener diodes. I’ve never been able to make it work.
It works fine with 1 watt zener, but 250mw is enough.
Don't forget to use 68 ohm series resistor like the circuit did.