Similar quirk from Sandbach on Sundays, had a lady with a Sandbach - York (possibly Advance) ticket, going towards Crewe.
Sure enough on checking it advised to go double back via Crewe, picking up a VT service towards Manchester, then same as usual. In these instances (times due to engineering work/set by NRE) common sense = no charge.
This could be to do with the "different" timetable on Sundays. Usually Mo-Sa the Styal line is a mix of FTPE/NT (Crewe via MIA) stoppers with skip-stop patterns, whereas on Sundays the NT stopper goes up and down to MIA, but the Crewe goes express to Heald Green, direct to Wilmslow, then as normal.
For those with going to MIA luggage, the connection time at Heald Green is plenty, albeit circuituous route between platforms.