I honestly will admit that the match between Manchester United and Liverpool will be a kind of trauma to Manchester United. The defeat was so huge that it will not be forgotten in a haste.
In as much as I am afraid that the loss may impact Manchester United negatively. I will also believe that the team has put themselves together and have trained within this few days. Therefore it will be an error to underrate Manchester United in that match. In fact, the lost against Liverpool could be a source of aggression to be transferred to Real Betis.
I think that MU will have a lot of desire to prove to everyone and first of all to themselves that it was some kind of accident. I am sure that ten Hag had a very serious conversation with the players, which should definitely affect their game. Yes, Betis is not the easiest opponent, but Manchester United should beat Betis. Betis have a good defense, I think that Manchester United will also try to play reliably in defense in this match in order to prevent something like this.
With this defeat, at least it can be a trigger for Betis to be able to beat Manchester United in the Europa League. Because at the very least, the big defeat might make the morale of the Manchester United squad unstable and not as good as when they beat Barcelona.
With these considerations, Betis will try to take advantage of the bad situation experienced by Manchester United.
But to be honest, for me a big team like Manchester United will be able to quickly move on from the bad result and focus on the next game. Because Manchester United previously managed to eliminate Barcelona, then that could also be a trigger for Manchester United to be able to go further in the Europa League.