We have ACH enabled for subscriptions in Zoho Billing and we have the option enabled for users to be able to log in to their bank to add the account to their payment methods.   Questions:

1) If the user's bank isn't supported via the log-in method, will it fall back to the micro-deposit method or will it just not allow them to use ACH?

2) For dunning settings, are the days noted for retries business days or calendar days?

3) Our changes to the dunning retry days do not save.    After changing, saving and exiting, the revert back to their default values.

4) There is a note at the bottom of the dunning settings that say that the dunning does not apply to the first invoice that a customer pays via ACH.    What happens when the first payment via ACH fails with the subscription?  Is it cancelled?  Are there notifications?  Do they show up on a report?

In our dev environment, we tested this and there appears to be 2 retries and a cancellation after the first ACH failure.   How did this happen?   https://billing.zoho.com/app/695841402#/contacts/2003936000002392436?filter_by=Status.All&per_page=200&search_criteria=%7B%22search_text%22%3A%22team_e_00113%40accountingsuitetest.com%22%7D&sort_column=created_time&sort_order=D