You are absolutely correct. It’s been doing this to images I shot in raw and JPEG with my Lumix camera set to B&W since v2.0.5 (v2.0.4 and prior handled them perfectly). I’ve reported this three times now with no response or improvement.
I raised a support request for this. According to Topaz, PAI is behaving correctly - if this were true then every other piece of software on the planet, including PAI up to and including v2.0.4, is displaying images incorrectly which I find difficult to believe.