goon teams often mirror their managers. I think Arteta lost it at some point (a possible unhinged Anfield ritual as per Burnwinter, lol), maybe became outwardly nervous, showed a loss of calmness and belief and the team’s performances followed suit. Wenger was a bit like this too and struggled at times to shake his teams out of bad spells before real damage was done.
These bad moments have occurred a few times now under Arteta. He needs to sort it out and it might be his head that needs sorting out.
You rarely, if ever saw a Man Utd side under Ferguson shit the bed like this.