Logic Masters Deutschland e.V.

This puzzle uses a slight variation of the rules for the puzzle ⟊ Mid-Loop ⟊ by ElChiglia.

Rules:
Normal Sudoku rules apply.

Digits separated by a white dot are consecutive. Digits separated by a black dot have a ratio of 2:1. Not all possible dots are necessarily given.

Mid Loop: Draw a single 1-cell-wide loop of orthogonally connected cells into the grid that does not branch or enter any cell more than once. The loop must pass through all given dots, and all given dots must be in the middle of a straight loop segment (i.e., the distance from a dot to the next turn along the loop must be identical in both directions).

The loop acts as a modular line. Each set of three adjacent digits along the loop must be one each from the sets [147], [258], and [369].