Weird note switching

I have a note I wish to be an F#, but when I set it to F#, the note before it (G) jumps down to the F line and the no sharp sign is displayed. This is on the top line of the treble clef. I'm not sure if this is due to some obscure music they thing or what, but it's mildly annoying.

Note: this is on a piano line and the pedal is activated.