Maybe it has to do indirectly with the competition, but I thought Barcelona played well for the copa del rey at times. I also notice that Frenkie the young scores more and more and gets free play. In that respect, Koeman is a good trainer. Now for the results. If Barcelona could keep on winning, they might have chances in the competition but they can not efford any mistake at all.
Barcelona has been great everywhere this year for the past few weeks, sure they didn't start amazingly at the start of the year but they have been great for the rest of it. If you do not consider the big loss they had against Bilbao at the super cup, they haven't lost since fifth of December. Juventus and Bilbao are the only teams they lost to in that span of time and all the other league games and cup games they have either won (mostly) and with few ties along the way.
So, basically they have found a fountain of youth once again and became the great Barcelona we all know about. Their only problem in the league right now is that Athletico Madrid has been doing very very well and that is why they are far away from the top, Athletico Madrid won 15 of their 18 games which is awesome, if it wasn't like that Barcelona would have been fighting for top spot right now.