P: Custom Order lost with slight accidental movement of thumbnail in filmstrip

This is something that's annoyed the cr*p out of me for years now too! It just takes a couple of seconds but doing it every time it gets a bit old. Every time I have to go back to Library mode and switch the "Sort:" to "Capture Time".  Absolutely unnecessary to have to do this. Have been seriously thinking about buying Capture One more and more recently.

Fine - will do.  At the moment it seems to be happening one in every 5 external edits in Ps.  No obvious reason, but I will keep an eye on things 

Keep me advised on your progress.

Oddly this does not happen every time an image is edited in Ps - it seems to be intermittent, and not for any particular reason or treatment in Ps.  I will monitor all edits in Ps to see if there is a pattern emerging

Sorry for the delay in responding Rikk.  Back at my Mac now and have reset all of the preferences as you suggest. 
I have just edited an image in Ps and on saving back to LR, the image and original have located themselves at the end of the folder gallery, therefore adopting custom order rather than capture order that the folder was set to.  Do you have any other suggestions as to why this is happening (I have just updated both LR, Camera RAW and Ps to the latest versions

Thanks for the advice Rikk. I'm away for a couple of days and will try as soon as I am back at my Mac. I'll let you know if this resolves the issue

Since I can't duplicate what you are seeing Nick, I am left with the good old chestnut: Have you reset your preferences lately? Some weirdness is cured by a reset of your preferences file.

1. Close Lightroom.
2. Hold down [Alt/Opt]+[Shift] while launching Lightroom.
3. When prompted, overwrite the preferences.
4. Close Lightroom.
5. Restart your computer. 

Does the behavior persist?

The only filter I use, if you can call it that, is to set to show images of 2 stars or greater. I start with all images having a 2 star rating, and raise to 3 star as editing completes (or reduce to 1 or 0 for rejected images). Other than than I do not apply any filters. I do assign a preset at import (for exposure, highlights, shadows, etc). Occasionally I set a colour to a photo, not for filtering, but as a reminder that I have combined two or more images in Ps, either as a layered image or panorama. Also set to auto-advance, when I change the star rating. Would any of these actions cause the date order to be lost, only when sending images to Ps ? (I normally work in folders, not collections). I look forward to any advice you can give, thanks

What I meant was, "Are you in a folder or a collection when you click on the image to send it to Photoshop?"

In any case, I tested it via starting in a Folder and starting in a Collection and in both cases, the Capture Time sort was honored before and after sending to Photoshop. It did not change to Custom Order in any event.

Do you have any filters active when you are viewing the images in your Folder/Collection?

I am editing the original Nikon RAW file from
LR in Ps. The photos are initially imported from a specific folder (in Finder) on my Mac. I never import direct from the camera, always download from camera to Mac and then into LR. Hope that makes sense Rikk