Balance reduction dBTC without transactions

After last night's dBTC problem, I updated my defi wallet to the latest version 2.8.3 released. I noticed that before the update I had a dBTC balance higher than the post update balance despite not having made any transactions. The other anomalous thing I noticed was that the amount in dBTC credited in pre-upgrade swap transactions was higher than the amount displayed post-upgrade. This explains the difference in the balance but it makes no sense as a confirmed transaction in the blockchain cannot be revoked or changed. The doubt that comes to me is that a reduction of the balance in dBTC has been made disguised through the correction of the amounts swapped in the transactions but this would mean that I am not the only one to have the private keys of my wallet and that the foundation can arbitrarily decide to withdraw funds from our private wallets. This thing happened to me on two different defi wallets installed on two different computers and I am 100% sure that the pre-update balance to version 2.8.3 was higher than the post-update synchronization. Anyone have an explanation?

Start by reproducing the reported balance and pre-upgrade swap-amount comparison across versions before and after 2.8.3 synchronization. Investigate the upgrade and blockchain transaction-processing entry points; no source files or tests are named in the issue. Done means explaining the discrepancy and confirming that wallet balances and confirmed transaction amounts are handled consistently.

Written by the indexing model from the issue text.