Delay in screenshot files appearing in Finder after taking screenshot

Thanks very much John. Q: In the cases where you've seen this happen, have they all been since High Sierra? Or have you experienced or heard of this happening on prior OS versions?

And:

"may just be the way screenshots work these days"

But this doesn't seem likely to me given user expectations conditioned from decades of near-instantaneous behavior in OS X, System 9, 8, 7, 6 — and, I just now looked— it was introduced all the way back on System 0.3 in 1985 !

And given that screenshots these days are an essential part of mobile devices, I think most consumers would never tolerate that, since they generally want to SHARE a screenshot with someone immediately, or post to twitter or facebook...

I could swear that screenshots on my Mac were "back to normal" the past few days, but in just now creating a few I can't believe, I counted 23 to 28 seconds for several to appear on the desktop, the fastest today being 7 seconds.

COULD THIS BE A FACTOR ?? Last night the last thing I did was turn on again Google's Backup & Sync, which I had to turn off the other day because while doing an initial sync of gigabits of files, it generated spinning beachballs so I'm guessing it's a processor-intensive function? Even now after 8 hours, the status still shows

(accidentally hit post) (continued: Google Backup & Sync hogging processor ?)

I will experiment by turning it off, then restarting my computer....

... Meanwhile I did find this thread here from 2013 (by Lawrence Lessig) describing the exact same screenshot behavior-- with over 2000 people saying "I have same problem", so I guess that answers "Is it due to High Sierra?" -- answer: No

That IS helpful to know, because my theory about an initial sync using Google's Backup & Sync to Google Drive is that function is hogging processor.... So it seems logical "Mac was busy doing something" may be the explanation.

Meanwhile, I did look through answers to the 2013 thread and saw an interesting suggestion which looked promising... but after I tried it, it worked once, but then back to delayed appearance on Desktop or Desktop Finder window:

designing divaLevel 1 (5 points)

by designing diva Jan 26, 2015 3:42 PM in response to Lawrence Lessig

I know this is waaay after the fact, but I had this issue also. My solution was to go to my system preferences, select the keyboard, then shortcuts, then in the left column select screen shots. All 4 boxes were selected (the default), I UNselected "Copy picture of screen to the clipboard," as well as UNselected "Copy picture of selected area to the clipboard." I left the other 2 boxes selected. Closed the window, and tried again. The image showed up on my desktop. Yay!

Then, following another answer in that thread, someone suggested to search for "Screenshot" (or whatever your default name is) and you will see your next screenshot show up instantly in that Search Results window. I followed this and very interesting:

quicksiteUSANov 15, 2017 1:47 PM in response to HectorLector

I followed this suggestion to experiment, then looked at the search results window (Searching "This Mac"Finder window) and tried a new screenshot: It showed up there immediately... and yet, not on my Desktop.

So I then opened two Finder windows side-by-side:

Search Results window for "Screenshot" ----- and ---- Desktop Finder window,

then created a new screenshot:

The new screenshot showed up almost instantly in Search results window --- but it took 27 seconds before it appeared in the Desktop Finder window. Same time-gap in several more tests. This time gap is very odd. Can anyone comment on what may be happening here?