Disconnecting run function block from new processor block causes Uncaught Error

[zfi]

Disconnection the 'run function' block from a 'new processor' block triggers an uncaught 'Connection lists did not match in length' error in Blockly core.

blockly.js:16908 Uncaught Error: Connection lists did not match in length.
    at Blockly.BlockSvg.Blockly.Block.getMatchingConnection (blockly.js:16908)
    at Blockly.InsertionMarkerManager.connectMarker_ (blockly.js:13489)
    at Blockly.InsertionMarkerManager.showPreview_ (blockly.js:13449)
    at Blockly.InsertionMarkerManager.maybeShowPreview_ (blockly.js:13445)
    at Blockly.InsertionMarkerManager.update (blockly.js:13375)
    at Blockly.BlockDragger.dragBlock (blockly.js:13556)
    at Blockly.TouchGesture.Blockly.Gesture.startDraggingBlock_ (blockly.js:14036)
    at Blockly.TouchGesture.Blockly.Gesture.updateIsDraggingBlock_ (blockly.js:14023)
    at Blockly.TouchGesture.Blockly.Gesture.updateIsDragging_ (blockly.js:14031)
    at Blockly.TouchGesture.Blockly.Gesture.updateFromEvent_ (blockly.js:14004)
    at Blockly.TouchGesture.Blockly.Gesture.handleMove (blockly.js:14054)
    at Blockly.TouchGesture.handleMove (blockly.js:14548)
    at HTMLDocument.a (blockly.js:20613)
    at HTMLDocument.n (helpers.js:72)

This appears to be triggered in the 'run function' block.

The 'run function' block is mutating to remove its bottom block connector when the block is attached inside a 'new processor' block.

When the 'run function' block is removed, the un-mutated form of the block returns and no longer mutates when reconnected to the 'new processor' block.

Sample project file:
Cog-Test.svg.zip