There have been reports of a couple issues occurring with installment based pages:
1. When a donor's payment fails on their first attempt, their second attempt reflects an adjusted total for the plan. For example, if the total donation amount is $200 paid over 10 installments, the total for the installment might be recorded as $40, with 10 payments of $4 charged to the donor.
2. Some newly created donation type pages that are saved for installment-based transactions are tracking donations as recurring. For example, if the intended total amount is $10, selecting to pay in 10 installments starts a recurring donation of $1 with no end date.
It is not clear if these two issues are related as the latter problem seems to preclude starting any successful installment plans. For context, these occurred with a page connected to Authorize.net as the payment processor.
Update: The first component of this issue has been resolved. Please email firstname.lastname@example.org if you encounter any issues that resemble this behavior.
Thanks for reporting this issue. We don't have a timeline for a fix but we will keep you updated here!