Well if it worked before they broke it, "average hardware" seems a bad argument to me. For example my iMac 2019 should be powerful enough to handle this (but I have this bug, too - also on other computers). It is just one of many bugs in Illustrator and if it does not appear on your machine, you are lucky. But don’t tell people to buy new hardware, because Adobe broke their software....

You can Solve it by Doing the following steps:
Go to Illustrator Preferences > Performance and un-check "Real-Time Drawing and Editing."
This happens because of average hardware. Get a better laptop I would say.
Check Something from here: https://expertratings.net/best-laptop-for-adobe-illustrator/

And today we've reached the v.25.2.2 and still haven't a fix for this bug!!!
Is it a joke?? The only solution at the moment is disable the real time preview but is a pain...

You mean a guide? Known bug. Disable GPU for now or try to drag a guide using Direct Selection tool.

I vote for a better fix to this, meantime however, there is another useful work around here:
https://dviz.me/guides-disappear-1c688
Especially useful for me is this little trick found way down in that post: place guides on a separate layer, and turn off "preview" for that layer.

I hate this! Why would anyone want their guides to disappear when repositioning them?? Big thanks to Anonymous for sharing how to turn this off. Very dumb.

Guides disappear when I drag them to reposition. They work fine when I drag one out from the ruler, but if I try to reposition, they are not visible when I drag and they appear when I release.

Unchecking Real-Time Drawing is just a poor workaround and not a fix! Adobe introduced even more GPU related Bugs with Illustrator 2021! Come on Adobe, don’t think of adding useless new features - FIX the existing ones, that we need to use every day!

Problem solved!
Go to Illustrator Preferences > Performance and un-check "Real-Time Drawing and Editing."
See attachement.

Problem solved!
Go to Illustrator Preferences > Performance and un-check "Real-Time Drawing and Editing."

Same issue here. Disabling GPU seems to solve. Is there a list of specific GPUs that seem to play nicer with Adobe going into future releases?

Known bug.
Vote here: https://illustrator.uservoice.com/forums/601447-illustrator-desktop-bugs/suggestions/39740689-realtime-preview-makes-rulers-and-objects-disappea
As a temp solution, disable GPU preview.

Please merge.

Dear ADOBE. Ive seen several comments from readers offering a solution by switching to CPU and disabling real-time drawing. And some of them even have responses from Adobe asking users to try the same thing. THESE ARE HACKS !! This is unacceptable. You are all like "YAY we've developed Real-time drawing with GPU to make your lives better" but when your customers discover that it screws up a fundamental basic such as guides, the solution appears to be NOT to use the new features !!

You have been 'refining this product since 1989, and you are a multi million dollar giant with huge teams of well paid developers. Just fix the guides !!!!

Guides disappear when moving with the Selection Tool, but not with Direct Selection Tool

Same here. 25.1 still has the same issue. Quite annoying. I entirely switched to operating with numbers within the transform panel instead of doing manual adjustments. I hope Adobe fix it soon.

Same Issue. Guides disappearing while moving them.

Hi, for me the same problem was resolved by switching to CPU (ctrl+E/cmd+E)
AND showing edges (ctrl+H/cmd+H).
This should make the guides visible at any time, while dragging them, too.

Thanks for that - that had me stumped and irritated for a while. They do these updates and have a bunch of boxes pre-checked on the preferences. So - in Preferences under Performance - Just deselect the the Real time Drawing & Editing - problem solved.

I had the same issue and Adobe told me to change some settings while this bug still happens:

Adobe:
Hi there, sorry to hear about this trouble. Could you please try deactivating Real time drawing from Illustrator preferences (Choose Edit > Preferences > Performance > Real-Time Drawing) and see if that helps.

Me:
I attached the bug to this comment.

As somebody stated, it also appears on v25.0.1. I really havent had this problem on v24 so I was baffled when this happened in v25.0.1. I did the Ctrl+E and it worked but the moving of objects and general flow became worse. I unchecked the "Real-Time Drawing and Editing" and it became a bit better. So I think the "Real-Time Drawing and Editing" is the villian here. I use Windows 10 and a laptop of some age but still powerfull for CAD and ofther workloads.
This issue is especially wierd when I am trying to move a completely white object (white fill, no line colour) onto another white object. Thats a challange :)