Zach Simonson, the Democratic Party chair in Wapello County, said that he had spent nearly three hours trying to report results on Monday. At one point, he received one call from a state party official who was “in a very loud room and screamed at me about wanting a precinct ID number but couldn’t hear my reply over the din in the room.”

“While I was talking to him,” Mr. Simonson said in an email, “my call on the other line, holding for 90 minutes, was answered and hung up.”

Mr. Depew, who had filed shortly after 8 p.m., said he had received a call from the state party almost three hours later asking for the results he had long since filed. “I said, ‘I already reported nearly three hours ago.’ She took my word for it and moved on without explaining the apparent snafus,” he said.

But those delays and confusion did not explain why the state party waited until Tuesday afternoon to release any results — including from the precincts that had successfully filed their results either via phone or the app.

The party said at first that it was conducting “quality control” efforts.

Much of the chaos unfolded off the main room at the Iowa Events Center, where campaigns struggled to figure out what was going on as party officials worked upstairs but refused to actually come down to discuss the unfolding madness, according to a person in the room.

At 10:26 p.m., the Iowa Democratic Party issued a longer statement.

“We found inconsistencies in the reporting of three sets of results,” it said. “This is simply a reporting issue, the app did not go down and this is not a hack or an intrusion. The underlying data and paper trail is sound.”

Around that time, the state party tried to brief the campaigns in a phone call. It did not go well. Party officials mostly reiterated their public statements: that the delays were related to issuing three metrics per precinct for the first time. Party officials hung up after being pressed for more by the campaigns, according to two people on the call.