I guess it's my old eyes, but I can't really see the white spots up close enough to tell. Could you take a close-up picture of one of the areas? Does the white spot wipe off if you try?

I can't see it either, but it's likely sap, a white liquid some Hoyas exude sometimes when bumped, or when a leaf breaks off or is injured. H kerrii is known to do this a lot, looks like Elmers Glue.

There was a question about this just this past week.

I can't see much of anything in this photo either, but with it being Hoya compacta, I bet my bottom dollar you have mealybugs. It's the worst for attracting them, which is why I don't grow it. A closer photo would help to confirm this. Look in the nooks and crannies, and if you find white kind of fluffy stuff, that's mealybugs. About all you can do is hit it with a systemic, like Bayer tree and shrub diluted as it suggests on the bottle. It's hard to remedy them topically because of all the nooks and crannies, but if you want to give it a shot, a sprayer with rubbing alcohol in it... But you have to get in all those twisty leaves, and leave it out of the sun for a few days. My sister has a huge one that got them, and she isolated it and worked on it for a year to get rid of them. But she did lick them finally!

No se ve bien la mancha blanca en la foto pero si es algo parecido a pelusa o algodón es probable que sea la mosca blanca o mosca algodonosa. Usa un insectidica "sistémico". Como ya te han dicho antes vigila si es "savia". La de kerrii presume de ser muy abundante. Suerte