AT&T believes its network wasn’t at fault for a conference call where President Donald Trump accused the company of being “totally unable to make their equipment work properly.” Instead, AT&T is blaming an unnamed “conference call platform.”

Earlier on Monday, President Donald Trump complained on Truth Social about apparent issues with AT&T’s network during a “major conference call with faith leaders from all over the country” that had “tens of thousands of people on the line.” Trump said that “this is the second time it’s happened” and that if “the Boss of AT&T, whoever that may be” would get involved, “it would be good.”

It appears AT&T initially wasn’t sure what was going on, as it replied to White House Press Secretary Karoline Leavitt on X to say that it had reached out to the White House ”to quickly understand and assess the situation.”

At 6:53PM ET, the company said that “our initial analysis indicates the disruption was caused by an issue with the conference call platform, not our network. Unfortunately, this caused the delay, and we are working diligently to better understand the issue so we can prevent disruptions in the future.”

AT&T didn’t say which conference call platform it believes is at fault, and didn’t immediately respond to The Verge’s question about that. The White House didn’t immediately reply to a request for comment.

Shortly after his original post, Trump followed up to say that the call may be rescheduled and that “we’ll use another carrier next time.”