Are you able to run this in a local or staging environment? If you can, you can enable debug mode which should show any errors, or at least show whats been submitted to the DB, if it is being submitted at all.
Ah yes, sorry I misinterpreted your question. As 3DS2 is new, it may just be a case of updating to the latest SDK's for them to be supported (Braintree only supports from v3), however I am unfamiliar with the payment flows used by providers other than stripe.
All transactions that take part in the European economic area will be subject to the new SCA regulations. It will be up to the individual banks to decide whether the transaction meets the SCA standards and to what extent they need to be meet. (Only the CMA 9 banks will be required to enforce SCA).
Here are some article outlining the regulations and who they effect
It looks like when you are importing the new product you aren't indexing them. As perch shop requires an index table to filter on it won't match the non indexed products, which is why saving is fixing the issue.
Hopefully the snippet below will help