“Adele killed it,” Justin Bieber told James Corden about Adele’s Grammy performance. Bieber joined Corden on a carpool karaoke drive around Los Angeles following the event.

Technical difficulties marred Adele’s return after her four-year hiatus. Many predicted it would be one of the best performances for the 58th Grammy Awards.

Adele visibly looked upset afterwards. The distressed songstress addressed the issue via Twitter.

However, many suspected Bieber was to blame for the glitches.

US Weekly reported TV audiences could hear “strange twangs and noises” throughout the start of Adele’s song. Viewers’ suspicions arose when Bieber played an acoustic guitar on stage. Fans immediately surmised the guitar was plugged while Adele sang.

Their reactions instantly poured on Twitter.

Academy President Neil Portnow also addressed the sound issue. According to news from Daily Mail, Portnow revealed the show switched to a backup sound system at the start of her song. This caused the audio to drop a few seconds.

Daily Mail also reported that Bieber’s set encountered problems, too.

After singing “Love Yourself,” the singer jumped off the stage and began to sing “Where Are You Now.” However, the sound dropped out briefly.

A spokesperson from CBS confirmed the broadcast had a five-to-eight second delay. However, the technical issue was beyond the network’s control, the spokesperson added.

In addition to sound problems, many users experienced problems with the CBS live stream.

A representative for CBS Interactive said, “Some users experienced temporary difficulty accessing the live online feed of the Grammys. Our location services provider had a brief issue verifying user location.”

The rep added, “That issue has since been resolved and all users are back online.”

However, Daily Mail revealed many viewers continued to have problems with the live stream during the show.