From @EWilfong_WMF:
I gave a one-time donation of $10 and received the upsell ask of $3. I choose the "give another amount" option and tried to give $4. I received an error message (attached) that I could not give more than my original amount.
- I wasn't trying to do that,
- I don't think that should be disallowed if someone wants to do that.
Oddly enough, I ran another test of a $5 initial donation and input $4 again as the monthly amount and it went through without the error message.