@anchor 'to: top' renders as a LEFT-side S-curve in Studio Pro; describe round-trips the authored sides so headless checks cannot see it

[MohamedGamalEzzatAli]

Summary

@anchor(from: bottom, to: top) on an edge between two same-column nodes renders in Studio Pro as an S-curve that enters the destination's LEFT side, not its top. describe echoes the authored sides back (from: bottom, to: top), so every headless check passes — mxcli check clean, mx check 0 errors — and the defect is only visible on the Studio canvas.

Environment

• mxcli v0.20.0 (windows-amd64, release binary)
• Mendix Studio Pro 11.12.1, MPR v2 project (created with mx create-project)

Minimal repro

CREATE MICROFLOW MyFirstModule.ACT_AnchorRepro ()
BEGIN
  @start(60, 200)
  @position(260, 200)
  LOG INFO 'top';
  @position(260, 360)
  @anchor(from: bottom, to: top)
  LOG INFO 'mid';
  @position(260, 520)
  RETURN;
END;

mxcli exec succeeds; mxcli describe microflow echoes the annotation verbatim:

  @position(260, 360)
  @anchor(from: bottom, to: top)
  log info node 'Application' 'mid';

Expected

Both activities sit at x = 260. An edge that leaves the source's bottom and enters the destination's top should render as a straight vertical line.

Actual (Studio Pro 11.12.1 canvas)

The anchored edge leaves near the source's bottom-left and enters the destination's left side, drawn as an S-curve. The same pattern reproduces in a larger validation microflow we authored: every edge written with to: top attaches on the canvas at the destination's LEFT, consistently across two flows (a microflow-call -> split edge and a split-true -> validation-feedback edge). Un-anchored edges in the same flows attach normally.

This suggests the writer maps the named side to the wrong stored connection port (top -> the port Studio treats as left), while the reader maps it back symmetrically — which is why the describe round-trip cannot see it.

Secondary observation

describe also emits a per-case split anchor form that mxcli syntax microflow layout does not document:

  @anchor(true: (to: top))

If that form is intentional, a line in the layout syntax topic would help; if not, it may be related to the same side-mapping.

Impact

Layout authored via MDL looks correct in every headless view (check, describe, coordinates) and wrong on the canvas a human actually opens — the class of defect that erodes trust in scripted authoring. Happy to test a fix build on this project.