The flashpoint came when China's Zheng was awarded an ace for 40-0 while serving at 4-3 in the second set, despite the mark appearing well out.
“Well with this thing, I won’t trust it at all,” Rybakina told reporters after her 4-6, 6-4, 6-3 victory sealed a spot in the last 16.
“Because there was no mark even close to what the TV showed."
The two-time Grand Slam winner compared the incident to Alexander Zverev’s clash with officials at the men's tournament in Madrid last year, when the German was penalised for unsportsmanlike conduct after taking a photo of a contested mark.
"It was, I think, similar to what Zverev had last year because it was in front of her nose. You can’t not see it. It was pretty frustrating," Rybakina said.
"It’s kind of a stolen point. I understand it was her serve and she was serving really well, but it’s really frustrating.”
Rybakina next faces Anastasia Potapova for a spot in the quarter-finals.