Every attempt to save an image as a TGA file results in a PNS file!
It seems that PSP 2018 is selecting the type BELOW in the drop-down list. (I assume it's not the entire list as haven't stepped through every type yet!) I had to choose TIFF to get my TGA.
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Terry, East Grinstead, UK
Using PSP 8 & PSP 2018 under Win 10