Moving a segment with Direct Selection won’t display an alignment guide to another segment
Smart Guides stopped working properly with the Direct Selection tool in v29.6.1.
For example, if moving a path segment with the Direct Selection tool, construction/alignment guides no longer appear relative to surrounding elements.
In the attached screen recording, an alignment guide should appear in relation to the left vertical sides of the two rectangles. You can see the intersection label is also missing when the paths touch one another. FWIW, the feature works in v29.6 and Beta with the same settings.
On a related note, holding the Command + Shift with the primary Selection tool is also disabled now.
Please fix this ASAP. This is a critical bug that severely limits productivity and quality.
AI 29.6.1

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onenower commented
This is related to the scaling ratio.
When the 'Smart Reference Line' is not displayed, enlarging the zoom ratio will show it. -
Odd... it works for me in 29.6..1, but on Windows, both with Direct Selection with a segment and Selection with Cmd/Ctrl + Shift.
Here’s a test file along with my Smart Guides settings.
Please help to investigate it further.