Gidday rickwest welcome to CS forum.
Is it new?....if so suggest direct your enquiry straight back to the vendor.
These thermostats are not adjustable, they are simply replaced if they fail although failure is relatively unusual.
There may not be anything amiss in the thermostat department. Are you operating it with the steam button depressed so that the machine operates way over coffee temp in the steam cycle?
Are you purging the group to check temp of brew water before applying the group handle and brewing, and are yoiu using a dark blend of coffee?
Not trying to be facetious but it could be technique related or caused by any number of variables and not necessarily the thermostat.