P: Saving copy not saving over jpg file

I don't believe it's an Apple issue at all. Flattening the file, then saving as a copy overwrites as it should. This is a Photoshop bug, or a UX oversight. It's very easy to slip up and forget to undo or revert flattening the file, resulting in further additional steps to restore the file (hello Time Machine!). I would hope this would be realized and "fixed" (if not a bug and done purposely).

I REALLY hope they fix this soon... it slows down my workflow and on tight deadlines, I, and other creators can't afford it.

Still not working / fixed.  Running macOS Catalina 10.15.2 and Photoshop 21.0.2.  Tested this on a '19 MacBook Pro and '13 Mac Pro.  Both behave the same.  Decided to find a fix today, but no joy... found this thread instead.

I fail to understand how this is an Apple issue.  If this was something to do with file duplication at Apple OS level, then I should see same / similar behavior in other applications as well, right?  Adding "copy" to file name is only happening in Photoshop...

I think this bug coincided with a splash screen in Adobe cloud manager or Photoshop about getting X amount of cloud space from Adobe in relation to the Adobe cloud account (that was bundled in with Photoshop).

Same issue here. Very frustrating.

Same issue here--I have to edit files in Photoshop while working in Lightroom and by golly, it always saves as a copy even though it indicates it is overwriting the original jpg, so I have to manually go back, find the original file, drop it into the trash, take off copy from the new jpg, go back to Lightroom and flip around a few times before it accepts the new jpg. VERY time-consuming. I have to take reflections off glasses and I dread it each time. 

It only started doing this to me with 21.0.2 in Catalina. It seems like every time they fix something they break something else.

Thank You, Leslie!  Now it works as it always had.

I am sorry that your experience is so bad.  My experience with Adobe support is much better.  If I were one of the Adobe support technicians, I am not sure I would be going out of my way to help a customer who thought I was a monkey.  I do think they have a problem triaging the support requests, many of which are likely resolved by consulting a cheat sheet.  Some of the request are over the head of the front line consultants.  It sounds like you have another issue than this annoying business with saving not resulting in writing over the original file when you tell Photoshop to replace.  I worked for 35 years as a software engineer and discovered that users cannot tell the difference between a 5 minute fix and 5 man-year enhancement.  Part of their problem is the upgrade by Apple to Catalina.  I am sure that Apple provided Adobe with a pre-release of Catalina.  I am equally sure that the version Apple released was not the same as the pre-release that they provided to Adobe.  I am scheduled today for a call from Adobe Tech support for an issue with Bridge.  Good luck to you.

What is truly sad and pathetic about Adobe these days is that they don't care at all about testing their software and try to pass off bugs as features. Gone are the days when software developers cared because it impacted sales. They have us on subscription now, do not care one bit. Pathetic.

I have stopped asking Adobe for any support of any kind because it is non-existent. There is just a room full of monkeys answering the chat/phone who simply look at a cheat sheet for the app and tell you what they read, not what they know. I too remember Adobe Illustrator 88 and getting phone support where the person clearly knew the app inside and out and was a professional. They use monkeys for this now.

Possible solution is for all of us to switch to Affinity Photo. Clearly Adobe doesn't care enough about its subscription base to want to do anything anytime soon.