It seems João Félix had a poor performance and his performance was weak enough to make Xavi mad at this player. Before João Félix joined Barcelona he said how loved this team and he wanted to play for Barcelona but this player mostly couldn't have good performances since he started playing for Barcelona,
In the game between Barcelona and Almería, the performance of João Félix was weak enough to make Xavi not use this player in the best squad in the game against Las Palmas.

Joao Felix performance might look bad recently that was why Xavi had to bench him in the match against Las Palmas but we can’t deny the fact of the contribution that Joao Felix have contributed to Barcelona since he joined the club on loan. His love for the club really improved his performance and this player should be a good player for Barcelona to keep as a permanent player. His recent weak performance is normal and it can happen to any player but that does not mean they should forget when he was still playing the best games for them. No need to slam this player because I am sure he will come back stronger than before after this moments of weak performance.
Felix's performance is unstable, it looks like he is returning to his performance when he was at Chelsea, very bad. Much different from when he first came to Barcelona, his performance was praised by many parties. Because in reality Felix only wanted to play at Barcelona, and after realizing his dream of joining Barca, he really enjoyed playing at Barcelona and since his debut with Barcelona, his face looked happy, this indicated that Felix was happy with Barcelona. But unfortunately now he is not included in the main team against Las Palmas because his performance has decreased.
If we're honest, Felix is actually not the player that Xavi really wants, but Laporta's dream player since 2021 has been planned. However, due to the financial failure inherited by the previous president, Laporta was able to take advantage of this opportunity. In fact, Barcelona is said to be the club in the UCL with the lowest player transfer spending this season. Laporta should be the next president of Barcelona like Florentino in Madrid, but unfortunately Barcelona has to change president every 5 years.