Sonoff SV, ESPEasy, servo MG90 wont turn ok

[Maxxelz]

Plan:
Sonoff SV + ESPEasy + Servo MG90 on GPIO05
Sonoff SV flashed with ESP Easy 2.0 mega and are workin ok.

But what could be problem with servo control.
If I connect servos yellow wire to Sonoff SVs GPIO05 and red to 5V and black to GND.
And try to control servo with commands
http://<espeasyip>/control?cmd=Servo,1,5,90

Servo jumps couple of degrees only.
If I connect servo directly to Sonoff GPIO5 and the V and G connectors it works better and servo turns but does not work ok.
I think that now the problem is 3,3V and servo needs 5V.

My plan was to use Sonoff SVs relay to give 5V to servo, only when servo needs to be turned.
Like
button pressed > relay on > servo to position X > relay off (this to save power and remove servo jitter)
but now I cant get it to work even with continuous 5V power.

EDIT: More information. So Sonoff is powered DC5V. And servo Vcc and GND is connected to same connectors.