Sage Barrista Express - Stopped frothing

Hi all,

I’ve had my machines or around 5 months now and up until maybe 2 months ago it was perfect. However, over the last 2 months I’ve been unable to froth any milk - The milk heats up, but i can’t get any texture out of it. I would normally assume it’s my technique, but for the first 3 months I was churning out perfect caps.

Any advice? Suggestions?

Thanks in advance,