More Contract and Date Issues

Hello,  I have additional issues around contracts and dates and what the corrective action is. This org I am with has a lot of data integrity issues. Here are 2 more scenarios of which I don't know the best way to approach them:   

1. In this scenario a contract was created with the dates below in the master agreement. But then evidently the contract "pushed" to 12/31/2023. Meaning the Master Agreement should have dates of 12/31/2023 to 12/30/2028. But the problem is that now that the last year of the subscriptions is renewing it creates a Master Agreement renewal that has the same term as the Master Agreement being renewed. 
   1. We have the concept of a Master Agreement (parent) with a related Subscription Agreement (child). 
      1. Master Contract  1. Overall cagreement  2. Start Date: 12/31/2021  3. End Date: 12/30/2026  Contract Term: 60 Months
   2. Annual Subscription Agreements
      1. Year 1 - 12/31/2021 to 12/30/2022 (term of 12 months)
      2. Year 2 - 12/31/2022 to 12/30/2023 (term of 12 months)
      3. Year 3 - 12/31/2023 to 12/30/2024 (term of 12 months)
      4. Year 4 - 12/31/2024 to 12/30/2025 (term of 12 months)
      5. Year 5 - 12/31/2025 to 12/30/2026 (term of 12 months)
      6. New the contract renewal is happening and it has a start date of 12/31/2026 and is for 5 years. When they actually want the contract renewal to occur on 12/31/2028. And the Subscription renewal to be 12/31/2026 for 12 months.
   3. Journal entries were made to correct the billing to start for subs that started in 12/2023. I can manually correct dates on the master agreement but then they don't align with the subscription agreements. I am stuck on how to move forward.
2. We have a case where a renewal was processed in June of 2025 for a 36 month term (6/30/2025 through 6/29/2028) and then they signed a new 24 month contract in April 2026 wanting the dates to be 6/30/2026 to 6/30/2028. It looks like someone manually changed the start date on the subscriptions on the contract from 6/30/2025 to 6/30/2026. How do I correct this since they manually changed the dates. I was thinking that the renewal opportunity would be used to adjust the dates but for some reason I feel uncomfortable with that thought or process.

Yes, the data in the org is a mess and I am now trying to help them correct some of these issues as they come up.    Any help is seriously appreciated.  Thank you.