As stated, one (and only one) of my credit card payment transfers is showing up not only in Bills but also in Other Spend. The other credit card payment transfers show up only in Bills.
My credit card payment transfers (and reminders of such) always show up in the "Excluded this month" section of Spending Plan | Bills as transfers like this:
The redacted information in the image above is as follows: For the negative transaction the first item is the name of the reminder and the second item is my main checking account; for the positive transaction the first item is the name of the reminder and the second item is the credit card account.
But just one of those credit card payment transfers, the one shown above, is also showing up (and is also as excluded) in Spending Plan | Other Spend like this:
The redacted information in the image above is as follows: Account = my main checking account, Payee = the name of the reminder, and the Category = my main checking account (same as Account).
The side of the transfer that is showing up in Other Spend is the positive side of the transfer (plus sign, in green), which would normally correspond to the transaction that appears in the credit card account. That transaction currently shows up as a reminder on the credit card reminder list, like this:
The only difference between this one and the other credit card payment transfers is that Simplifi erroneously matched this $1621.04 payment with a $10.32 refund on the card. Undoing the match resulted in there being no payment scheduled for April at all (which is a different problem discussed elsewhere). So I had to change the "Start Date" of the series back to Apr 8, 2026 and edit the amount to put things back like they were.