Retrospective applicability of Hindu Succession Act 2005 amended in 2018

There is a HUF with four sons and two daughters. The 2 daughters were married in the 1990s. The father of this family died in 2001, so the elder son, Y, became the Kartha. He had an adult daughter. In 2006, Kartha, his adult daughter and his 4 brothers sold the entire land of 7 acres to one X due to financial difficulties in the family. According to the then law in 2006, the daughters did not have the right to ancestral property if their father had died before 2005 and if they were born before 2005. So, applying that law, Kartha sold the property to X in 2006 without including the daughters. In 2009, I purchased the property (2 acres) from X by applying the same existing law. I purchased in parts, once in 2009 and some in 2010 and 2015, and thus bought 7 acres in whole by 2015 and got it converted to DC. My Purchase was legal as per the then-existing Hindu Succession Act, which was introduced in 2005. The High Court had upheld this law in Prakash vs Phulavati . on 16 October 2015 But in 2018, in the ruling of Vineeta Sharma vs Rakesh Sharma on 11 August 2020 The SUPREME court amended the 2005 law, giving daughters full rights to share in ancestral property by birth irrespective of whether the father is alive or dead and MADE this law retrospective. The Kartha Y died in 2021. Now, the 2 daughters, after 16 years of the original sale, have filed a partition suit in the court claiming their share. What is the Apex court's clarification for this situation? So, what is my situation now? I applied the existing law when I made the purchase and paid full sale consideration. The Apex court has amended the law and made it retrospective. Which law should we Indians follow? How certain are we about today’s law if it can be changed in the future and made retrospective? What about my constitutional rights over my property, which I purchased by applying the existing law?