The origin of "It's just one of those things"?

According to the following source the phrase popular after a famous Cole Porter's song:

Just one of those things: (noun phrase)

• Something that can hardly be predicted, justified, explained, or avoided, but is an intrinsic and sometimes a distressful part of living •The gestural equivalent is a shrug : Their divorce was just one of those things (1930s+)

  • A random occurrence that can't be explained. For example, It wasn't their fault that the show failed; it was just one of those things. This expression was given greater currency as the title and refrain of one of Cole Porter's most popular songs (“Just One of Those Things,” 1935). [c. 1930 ]

Source: www.dictionary.reference.com

According to this ngram, the phrase dates back at least to the middle 1800s, and usage to convey the inexplicable can be found in numerous examples around the turn of the century, for example

But it was just one of those things which occasionally come to pass ...

The Grey Monk in The Argosy, Volume 57 (1894), edited by Charles W. Wood

I suppose it is just one of those things which happen.

The Ambassador: A Comedy in Four Acts (1898) by John Oliver Hobbes

We do not understand it, and are apt to dismiss it as "just one of those things." In these lessons we are attempting to explain some of "those things," and to enable you to use them consciously and understandingly, instead of by chance ...

A Series of Lessons in Raja Yoga (1906) by Yogi Ramacharaka, William Walker Atkinson

Don't you think I'm blamin' you, Jim. It's just one of those things that's got to be.

The Call of the Hills (in The Black Cat, Volume 11) (1905) by Lucretia Dunham Clapp

I have no reason to give. I do not think that there is any willful intention to do anything wrong on the part of the Government or the Commission. I think it is just one of those things that happen, possibly, with a number of officers in different lines, ...

Investigation of Panama Canal Matters: Hearings Before the ..., Volume 4 (1907)

There are a few earlier examples that seem to convey something similar, such as

If we might be permitted to quote from Dundreary, we should tell you that who St. George was and what he did is “just one of those things that no fellah can find out."

New Outlook, Volume 10, (1874) edited by Alfred Emanuel Smith, Francis Walton

“Just one of those things” was a song written by Cole Porter for the musical Jubilee in 1935. The lyrics are online, but although they include that particular phrase it doesn’t appear to have much to do with “an event you do not like but cannot change,” or indeed, to “an event or situation that you cannot explain.” In these rather wistful words it seems to be expressing “something which was inevitably short-lived and bound to pass.”

It was just one of those nights
Just one of those fabulous flights
A trip to the moon on gossamer wings
Just one of those things
If we'd thought a bit
Of the end of it
When we started painting the town
We'd have been aware
That our love affair
Was too hot not to cool down
So good-bye, dear, and amen
Here's hoping we meet now and then
It was great fun
But it was just one of those things.

— Cole Porter via rock.genius.com

It’s not really possible to tell whether Cole Porter was reflecting a fairly widespread use, or using a phrase he’d picked up and giving it currency in his popular work. However OED has an earlier reference, from 1922, which certainly fits the “inexplicable” meaning:

1922 R. D. Paine Roads of Adventure xxii. 228, I wonder if we could blast the secret out of a French dictionary. Probably not. We shall never know. It is just one of those things.