Heatmiser - Time data '255:00' does not match format '%H:%M'

I’m using this integration (GitHub - MindrustUK/Heatmiser-for-home-assistant: Heatmiser Neo-Hub / Neostat support for home-assistant.io) to control my heatmiser heating system but it has all of a sudden thrown the below error and now won’t work.

Retrying setup: time data ‘255:00’ does not match format ‘%H:%M’

Any suggestions on how to fix this?

TIA

Anyone help?