How to make it stop updating the rate?

Hej,
I decided to do manual updates on one conversion rate from SEK to EUR. I found the option to have it so it update automatically only once per month instead of more frequent, so, I set it to that, and then change the rate manually.
The problem is, that it keeps updating automatically frequently anyways. Please help on either fixing this what seems like a bug in your software, or give me another way to solve this.
Br
//Joel