Hi,
indeed you should use "CANON EOS 850D" as "make_model" (all uppercase), and then it should work (it works for me at least). Blame Canon for using different names for the same camera…
Yes, and I’ve blamed them before. 
Their multiple names, particularly when combined with case-sensitivity, have sent me scurrying more than once in the past.
Well, at least it works now! Thanks.