String buzz on first and second frets

[Tone71]

So, I was pretty happy with my recent acquisition (Sigma 000m-15) sure its a cheapy and once the new guitar gloss has worn off its just essentially another cheap acoustic........however.

Over the last few days maybe a week I have noticed the strings buzz when fretted on the first or second fret, this is a new thing it wasn't like this before, the only thing i can think off is that I hung it on the wall in the extension which gets colder overnight than the rest of the house except from that nothing has changed.

I have had this before with electrics but with a bit of mucking about it gets rectified, thats the joy of bolt on necks but obviously this is a set neck.

Is the only option to raise the action?

[octatonic]

Check the relief first.

[Tone71]

Thank you sir, all sorted