The Manchester United rollercoaster reached an exhilarating peak on Thursday night - but the problem with rollercoasters is that what goes up must come down, and United hurtled to the bottom at a rate of knots four days later.

The only people really getting a thrill from this ride at Old Trafford are the visiting fans. United rescued themselves against Southampton, but even that - against the worst team in Premier League history - came with plenty of caveats. Just about every other team looks likely to win here at the moment.

This was Brighton's third win in a row at Old Trafford. Bournemouth have won their last two trips here 3-0. It's the Theatre of Screams for United fans, and that's a ride that sounds like it belongs at a theme park.

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It was Ruben Amorim who predicted his team would resemble a rollercoaster after the win on Thursday night. He probably didn't expected to be proven right so quickly, although given that comment perhaps he did. The 39-year-old doesn't seem to know what he is going to get from one week to the next.

There is a trend beginning to emerge, however. Old Trafford bad, away from home not so bad. Sometimes even good. It's hard to describe the biggest club stadium in English football as a problem for the team that plays there every week, but that is where we are.

Before kick-off, Old Trafford had shown off its power and its stature. The tributes to Denis Law struck the perfect tone, but the farewell to a true Old Trafford legend, the man dubbed the 'King of the Stretford End', didn't lead to a brighter start from a team beginning to look burdened by the weight of this stadium.

For the fifth time in a row, United conceded the first goal at home. In three of those games they conceded inside five minutes and in all of them they conceded in the first half. It's a desperately poor record, but it isn't confided solely to the start of games either.

They conceded twice in the first 10 minutes of the second half against Forest, twice in the first 18 minutes of the second half against Bournemouth and now 15 minutes into the second half against Brighton.

In a way, it sums up United's home failings. They are still a team built to play on the break, to sit back, soak up pressure and counter. At home, they are expected to make the running and they can't do it. Teams are finding it easy to let United have possession and defend against them.

In the end, it was Amad who broke down Southampton on Thursday. That 12-minute hat-trick looks absolutely vital to United's season as things stand. He is the only player looking like he will make something happen going forward when there aren't spaces to exploit.

Away from home, there have been signs of Amorim's method beginning to make sense. United played well in large patches in a Carabao Cup defeat to Tottenham. They were good at Manchester City, Liverpool and Arsenal and got positive results in all three.

But in front of their own fans, it is now four defeats in five. There is also something in the calibre of teams United are getting results against. They are holding their own against the big boys and Amorim and the players have made it clear why they think that is, putting it down to attitude and character.

But there is more to it than that. Against those sides, United can play defensive football but they will equally get room to play. Amorim said it best after he guided Sporting to that 4-1 win against Manchester City, suggesting such defensive, reactive football wouldn't be acceptable at United.

At the Etihad, Anfield and the Emirates, it is, and that is why United have looked good in those matches. The challenge is coming in games they should dominate. They lack the tools and the training ground patterns to break down those defences.

This was another example of why United have to find some wriggle room to do something in the January window. If Amad isn't firing, then neither are United. The lack of goals in this is one of the biggest reasons they are likely to finish in the bottom half of the Premier League.

After watching Rasmus Hojlund toil for a few weeks, Amorim turned to Joshua Zirkzee. But Zirkzee looks good when Hojlund starts and Hojlund looks good when Zirkzee starts. The reality is that neither are good enough for Manchester United and the £108million it cost to sign them is another example of the woeful recruitment that has brought the club to its knees. Now, the only set of players that look fearful of Old Trafford are the ones playing in red.