Beyoncé's Opening Concerts Marred By Tech Issues, on Video

Beyoncé's "Cowboy Carter" tour is off to a rocky start ... not only at the box office, but onstage too -- 'cause a couple errors by crew members seemed to have the pop star fuming.

The singer-songwriter performed at SoFi Stadium in Los Angeles this week ... and, while marching down the stage during one of her shows, she looked to the ground to find her mark.

The Queen Bey appears shocked and turns around, searching for the "X" to mark her spot ... but, she can't seem to find it -- and, basically guesstimates where she needs to be.

Beyoncé pretty much nailed her spot ... good news, since heavy-looking picture frames on robotic arms come down in front of and behind her -- and, she would've taken one heck of a shot to the head if she hadn't made a slight adjustment last second.

It wasn't the only issue Bey had onstage during her first string of shows this week ... 'cause at a different moment, she was supposed to go up in the air atop a neon horseshoe -- but an issue with her glove had a crewmember standing out way too long to fix it.

It's unclear what this backstage bro is trying to fix here ... but, you can see it in the Queen's eyes -- she looks like she wants to order his beheading.

Bey's got a couple more shows in L.A. before leaving for Chicago ... where hopefully she's having better success selling tickets. Like we told you, sales are way down -- with fans seemingly unwilling to pony up the cash to see this cowboy.