Please explain this put option

I don't know what they are right now because GME is halted but in the past week, bid/ask spreads have been wide for GME options. That's a small reason why your put may not be increasing as fast as you'd like.

The major reason is that options gain in value when implied volatility increases and they lose value when implied volatility decreases. So if there's a large underlying price move in your put's favor (GME drops 30 points) and the put loses money, it's because there was a sharp contraction in implied volatility.

However, given that GME is down $111 when halted, your should be rewarded for your cohones (buying GME options in this environment) if it doesn't rise sharply when trading resumes.

Given the lag in option spreads becoming sane, you can lock in the gain by buying shares if you have the cash to do so.