Initially installed polyester capacitor forgot to mention both 220nf caps are popyester 630v.
Frequency in screenshot is stable i i took a shot right when i adjusted to 50.8hz after that screen was scrolling with 50.8hz .
It does react to the pot but minimum value is not less than 1.9-2ms . If pot turned the opposite side i am getting very high duty cycles.
Will replace pot with fixed resistor see what will happen.
I suspect breadboard connection and resistance of wires. I had issue with wires on esp8266 circuit and solved only soldering them.