Adjustment of LTCG on cancellation of property registration

Dear Esteemed experts, I had purchased an under-construction property (property A) from a builder in March 2022, for which construction stage-wise payments are still going. In FY 22-23, I had sold another property (property B) and used that money to pay for Property A. I had claimed exemption of LTCG arising on sale of property B for FY22-23 as I had invested that amount in purchase of property A. A registered sale deed agreement was executed by the builder of property A and the property is still under construction. Due to some circumstances, I am planning to cancel property A and shift my purchase to another under-construction unit in a different tower by same builder (say property C). To do this, the builder suggested that we need to cancel the existing sale agreement of property A, and they will be making a fresh booking for the new unit as property C. The builder will not make an internal transfer of already paid money and will be returning it back to me. Thereafter, on registration of property C sale deed, he will be raising fresh demand letters based on construction stage of new property and I will need to pay him for it as a fresh booking. In such a case, how will the LTCG claimed as investment in Property A be handled? There is no real income arising from cancellation of property A as the builder will only pay me the amount I paid to him so far less the TDS deducted by me. Will this cancellation and transfer to new unit be treated as Sale/Transfer of Property A and fresh purchase of Property C? I will be thankful for your insights on this scenario. Thanks.