Renegotiation of Contract cancellation Fees/recording on the books

Hello, I had a contract for an event in September 2022, though in 2021 we decided to cancel, and we had to pay per contract 50k cancellation fees, we said we can't pay that much, and they agreed to 10k so that is what we paid in 2021. I recorded the 10k in prepaid in 2021. No I am planning to recognize the expense in 2021 Sep. but do I need to record a liability and forgiveness for the 40k that were renegotiated and do I need to record them in 2021 or 2022?

Thank you