Options selling query

Hi Trading Community, On 2nd Jan '25, I took a trade in Banknifty (Jan exp, option selling, long) with the strike price of 51000 PE (ATM). While the price moved up by 1%, the premium didn't decay much. Even in initial 10 candles, even if it was moving in my direction, it showed loss. Can anyone tell me the probable reasons for the same? Attaching the snapshots: https://preview.redd.it/j38tt9qd8uae1.png?width=1752&format=png&auto=webp&s=56e04e7657d3bee1f5c46c9e762252340ea20d7d