I am having the same issue (November, 2023). I noticed that the thread started more than a year ago. Any solution, yet?

Illustrator version 27.9
Photoshop version: 25.0.0
OS: Windows 10 Home 22H2
Multiple monitors

If grab and move application frame, the application frame snaps back to it's original position. i.e. the application frame can't be moved. However it can be resized. This is occcuring in both Photoshop and Illustrator.

Steps to reproduce:

The application frame is not full screen size.
Click and hold the top of the application frame and drag it to the new position.
Let go and it should drop into it's new position, however it appears back at it's original position.
The application frame can be resized or maximized to full screen.
When it's full screen, it can be dragged to become a smaller frame but it snaps to it's previous location. i.e. it can't be dragged to a new location.

Reinstalling illustrator does not resolve the issue.
Reverting to Illustrator version 27.7 solves the issue. (So it's something to do with recent updates)

We tried unplugging each monitor alternately, then both, no change
We also have tried
1. turning windows fast restart off and restarting again
2. using Shift close to set a new starting position, which worked but didn't solve the overall issue
3. made sure tablet mode was already off, settings weren't available to toggle
4. toggled windows animation settings, no change throughout
5. sfc /scannow and restart let us move window freely as computer was shutting down, but after restart we were back where we started. Could not duplicate
6. toggled span windows setting, which broke workaround temporarily, but no change in over all issue
7. updated graphics card, no change

I mean, does it help to physically unplug the monitor?
A software plug is good, but it does not mean it works for all cases.

the Win+P workaround I mentioned does turn off each screen as part of cycling through, and this does change the position of the Illustrator window. It still keeps snapping back to wherever it ended up though.

I also tried resetting Win graphics via CTRL+SHIFT+WIN+B since my original comment, but no change there either.

Never had anything like this :/
Does it help in any way to temporarily disable the second monitor? Just to exclude the dual-screen causes completely.

Version : 27.8. 1
OS : Windows

Grabbing the top bar and attempting to move the window will generate the outline, but when we release it snaps back to its original position. Same for using the native alt + M method for repositioning the Window.
I can resize all borders except the top, and it responds to win + directional keys to snap to a side and switch monitors as a workaround
The issue repeats as soon as we unsnap from the monitor border, it will then start snapping back to its new position
Similar to https://illustrator.uservoice.com/forums/601447-illustrator-desktop-bugs/suggestions/44914921-click-drag-fails-snaps-back but on Windows and with most recent version of AI.
Happens on new and existing files.
Restarted computer, no change, Cycled screens between left/right, duplicate and extend using win+P, no change, reinstalled Illustrator, no change.
No other apps, adobe or otherwise, are having this issue.

This has been happening to me for a while too. Updated today (10/10/22) and it seems to be working properly.

I just started having the issue today, and I updated version 26.5 a couple of weeks ago. I found this thread looking for a solution.

Drag and click to align is definitely is NOT working in the latest version of Illustrator. Please fix.

It is now October 1st.

With the latest update to Illustrator (26.4.1) click-drag and click-option-drag fails to move even simple objects within the artboard to a new location. The shift key makes no difference either. When I click over the object a "+" sign appears, I'll drag the object and hear a pop alert sound and the object snaps back to where it started. After multiple tries I can sometimes get the object where I want it, but as soon as I release the mouse everything else around the object moves away as if they were reverse magnets. Using the arrow keys can move the object but takes far too long. This problem is infuriating and adds multiple hours to every job, and I can't bill for all of this extra wasted time.

Adobe, this needs to be fixed immediately!

I originally posted this in Community Forums for ver 26.1.

https://community.adobe.com/t5/illustrator-discussions/frustrating-selection-tool-behavior-with-ver-26-1-on-macbook-pro/m-p/12837070#M315539

The frustrating behavior is back in ver 26.4.1 and I am also using Illustrator on my iMac.

Had the same issue. Had to wipe my drive and reinstall earlier this week, which is how I wound up on 26.4.1 and it began happening afterword. Thought I was losing my mind.

I don't know where 26.5 is  — it's mentioned on Adobe's website as being the latest version — but as of right now, both CC and the Adobe site direct you back to 26.4.1. For the present, I rolled back to 26.3, which seems to have solved it.

Oddly, I noticed a repeat to the bug. Objects would "snap back" (along with the default system error sound) four times. After the fourth error, it would work correctly. Seems to have behaved this way pretty consistantly.

Illustrator 26.4.1
Mac OS 12.5 (21G72)
MacBook Pro (16-inch, 2019)
2.4 GHz 8-Core Intel Core i9
Magic Mouse 2

Forgot to mark it as critically important. I can't work in this version of illustrator like this. Please fix it.

This is a nightmare. I rolled back versions and still can fix it. My workrate has slowed down considerably because every single task is a chore. Please, Adobe, fix this.

This problem is occurring for me in version 26.4.1. If I use my apple track pad then I don't have the problem. This is very frustrating

Hi everyone,
With the new update (26.5), the problem we are having looks like gone. Hopefully it won't come back. Thanks to everyone for expressing their frustration on the issue. Knock wood we are good to go. If anything changes, I will update the situation. Also thank you Egor for raising the issue. Cheers

Hi jonbrong

I switched between an Apple Mouse II and a Logitech Mouse several times during my tests. In the process, I switched the mice on and off several times. This had no positive effect on me.

But nice if it helped you - possibly the problem was multilayered.

Many greetings Peter

May sound stupid but...

I just turned my Magic Mouse 2 off and then on and the bug appeared to go away.

*fingers crossed

Same problem here. Very frustrating. SOLVE IT!