Built engine, new timing belt.
AMU engine.

First start, runs rough.

Timing blocks in VCDS Vagcom (block 090 to 093) show "99 degrees" and error code "cam sensor and engine speed sensor correlation".

Timing checked. Crank at TDC mark. Cams 'square' marks both line up with mark on bracket, exhaust cam timing belt sprocket mark lines up with valve cover mark.

Timing chain has 15.5 links between marks (counting first link on mark, 16th link just past mark).

Any suggestion what might be causing issue?