[GNC] Reconcile also opens Interest Payment box?

[lj]

Using GnuCash-3.10 on Linux, self-compiled (soon to upgrade to 3.11)

For just one of my accounts, the following odd thing started happening this 
month. I open the register and click Reconcile.  The expected Reconcile 
Information dialog box opens, but on top of that I get an Interest Payment 
box. Why would this pop up over Reconcile? Why only for one account? It 
started this month. What did I do to cause this?