I also think the same as you that even though Liverpool lost in the FA Cup, that doesn't mean Liverpool will also lose to Manchester United in the Premier League. In fact, I am quite sure that Manchester United will not be able to beat Liverpool in the Premier League. It's just quite unfortunate. Because while many people are starting to expect Klopp to get lots of trophies this season with Liverpool, Liverpool are actually starting to miss opportunities one by one to win trophies. Now only the Premier League and European League remain. And I hope Klopp doesn't fail to bring his troops to lift the trophy on the two remaining occasions.
Lifting the remaining two trophies will be a difficult task for Klopp, but I am confident he will do his best to win at least one of them for his team. In the Premier League, Manchester City and Arsenal are major opponents who can deny him the league title, while in the Europa League, which appears to be easier to reach the finals, Bayern Leverkusen may be their opponent for the final match, which does not appear to be an easy trophy to win. I haven't lost hope in Klopp and Liverpool yet, but their performances from now until the end of the season will determine what they can achieve by end of the season. Losing to Manchester United in the FA Cup doesn’t mean they’ll do the same in the premier league. These are two different games and are played with different intents on how serious they’re to them.