Loss of signalling earlier at Heaton Norris.
I believe there was also a signalling issue somewhere around Stockport on Saturday morning (the first day) which caused some delays. To compound this, some of the northbound Avanti and XC were running late due to delays elsewhere and this complicated the situation. Some trains were taking 20 minutes for the short distance from Cheadle Hulme to Stockport (usually 4-5 minutes), presumably awaiting a platform.
I used the coach replacement from Huddersfield to Stockport this weekend. it worked ok. A decent coach with good luggage space. The journey ran smoothly until turning onto Wellington Road (the street from the motorway to Stockport station) where it was gridlock. it took over an hour for the journey but it was easy.
There have been plenty of reports locally about traffic congestion on the A6 (Wellington Road) due to more road traffic accessing the station. For those unfamiliar with the station, there are two road accesses on the east side of the station, both cul-de-sacs and both controlled by traffic lights. The northern one is reserved for buses but is also an access for the local McDonalds on Wellington Road which has a small cark park and is also a drive through and it appears the congestion is caused at this junction by traffic not being able to move along towards the station.
I caught a normal service bus into Stockport yesterday which passes through this junction northbound and it was bob on time until about 800 yards from the junction and finally arrived in the bus station 6 minutes late. The queue southbound on the A6 looked to be about a mile to this junction. There are a lot of traffic lights on the A6 through Stockport and road narrowings too which doesn't help.
I couldn't see exactly what the problem was on the station approach as the view wasn't great from the bus, but there were some guys moving orange barriers around, but I have to go in again in a couple of days when I will have a chance to look in a bit more detail at how they are dealing with the RRBs.
Meanwhile the town appears to be awash with RRBs; the service bus I caught home doesn't use the A6 (due to the Greek St bridge diversions still in place

) and there were at least 4 RRB double-deckers parked-up on the road behind the Town Hall awaiting their next turn.
I have also read on a local board that the Northern RRBs all stations Stockport-MAN have been binned and passengers are advised to catch the 192 service bus instead - runs every 3-5 minutes. They are certainly not showing on RTT anymore.
Hopefully experience of the last couple of days will men that some of these issues delaying the RRBs will be resolved resulting in less missed connections.