when you make a compound word by hyphenating it you capitalise it and treat it as a single word, due to the hyphen. They also mentioned some compound words later morphed through heavy usage to be a single word without the hyphen.
There are two distinctly different situations. I will use my invented expressions, "permanent" and "temporary" hyphenations.
A permanent hyphenation is one that dictionaries list with a hyphen. You use a hyphen for them in all situations, if you're following the spellings of a dictionary. I always treat those as a single word.
I include in that category anything that connecting a prefix - actually, anything which cannot exist as a word on its own - to something else.
However, "permanent" hyphenations often do not last long in everyday usage. For example, I expect about a hundred years ago some dictionaries listed a noun 'make up', meaning cosmetics. At that point, I would have treated that as two words. Later on, the same dictionaries would have listed 'make-up', and nowadays they list 'makeup'. I would have treated both of those as single words.
The example CW asked about, 'home-port issues', is one which I consider a temporary hyphenation. The hyphen is only required because the expression is being used as a compound adjective before a noun. I consider that as two words, and dictionary.com does too! If you enter either 'homeport' or 'home-port' into its site, it returns its definition of 'home port'.
EB, having made that point, I would NOT go the further step and say the capitalisation of one- and multi-word hyphenated expressions should necessarily be different. My style is to treat them differently. I wouldn't assert it is invalid for others to treat the both in the same way. However, I am convinced careful writers should recognise they are different, and make two style choices for how to capitalise them.