Home Assistant Cloud + Alexa + Thermostat not working

Hi, I’m trying to add my homematic thermostat to Alexa with the HA Cloud but whenever I try to access the Thermostat in the Alexa app I simply get an error and home-assistant throws the following error:

climate.oeq2099702 (<class ‘homeassistant.core.State’>) has unsupported operation_mode value ‘manual’

Does anyone know how to fix this? Thanks in advance!

EDIT: I have just now noticed that it does indeed change the temperature (but not modes), but Alexa just say “Bedroom Thermostat is not responding”

EDIT2: OK, so it will let me set it to automatic, but not back to manual or any other setting. It still says “is not responding”, though.

EDIT3: if the thermostat is set to “Auto” there’s no error message from alexa, she just sets the thermostat. Thought this might be relevant as well.