Guides are not aligning with artboards even when "Align to artboard" is selected.

There once was a very old bug that caused some funny movements when aligning guides to the artboard while the Use Preview Bounds option was turned on in the flyout menu of the Align palette. It was called the "somersault long jump bug".

Some years ago this bug was fixed. Well, at least almost. In fact, the bug may still appear sometimes, but not just out of the left field. It's a reproducible issue in conjunction with grouped guides.

For example:

- Create a guide and make sure it's unlocked.
- In the Align palette menu, turn on Use Preview Bounds.
- Group the guide.
- In the Align palette, align the grouped guide to the artboard.

Right Aligning will now catapult the guide from Alaska straight to Portugal. Left Aligning from Honolulu to Novosibirsk.

To fix the issue, just ungroup the guide. Aligning should then work as expected.

There may be some other strange reasons for the behaviour you are describing, but the grouped guide issue is one that can clearly be replicated.

Not knowing your level of experience, and lacking a step-by-step description of what you have done, I am led to wonder if you have selected Align to Artboard in the Align panel, then expected a guide to automatically align to the artboard when you drag it out of the ruler, which does not happen except as Laura Coyle. has mentioned.

On the other hand, have you:

1) Generated a guide, either vertical or horizontal, from the ruler

2) Selected the guide

3) Opened the Align panel

4) Selected Align to Artboard

5) Clicked on Horizontal Align Left (or Right) or Vertical Align Top (or Bottom)

and it still aligns randomly? A fuller description and/or screenshots might help our understanding.

Thanks,
Peter

I can't replicate your problem, they align to the artboard. If you did what @Laura Coyle. suggested and are still having the problem, I would also try restarting your computer. Then if it persists, come back and let us know more about your system and what version of CC you are using so we can further troubleshoot.

My apologies, I see that's not what you were asking! I just tested, and I'm not having that issue. Hopefully you don't have more than one artboard in your file, that is activated. If it's a buggy issue, clearing preferences can help: https://helpx.adobe.com/illustrator/kb/troubleshoot-preference-issues.html

my previous answer: Do you have Smart Guides enabled? View > Smart Guides. When you move a guide close to an artboard, it will snap.