I managed to find an actual statement of Turkish officials, snippets of which were quoted and paraphrased in the press, although apparently there were more:
Turkey President Recep Tayyip Erdogan has said that Ankara will not allow Syrian regime forces to gain ground in Idlib province, the last rebel-held area of Syria in comments published on Tuesday, a day after the Turkish soldiers died in regime fire.
"Syria is right now trying to buy time by driving those innocent and grieving people in Idlib toward our borders. We will not allow Syria the opportunity to gain ground there," Erdogan said in quotes published by the Hurriyet newspaper and broadcaster NTV.
"This is a clear violation of the Idlib agreement. There will of course be consequences for the regime," Erdogan said in the interview, which was given to Turkish journalists on his plane returning from a visit to Ukraine.
Erdogan had earlier criticised Russia, the key backer of President Bashar al-Assad's regime, for failing to enforce peace agreements in Idlib, but he toned down his rhetoric in the latest statement.
"We don't need to get into a serious conflict or a serious confrontation with Russia at this stage," he said. "As you know we have very serious initiatives with Russia."
So yeah, it was seemingly rather general criticism of "failing to enforce peace agreements" (in Turkey's view) by not reigning in Assad. A bit more searching found quotes from those prior statements, but they weren't anymore specific:
"Currently, Russia is not abiding by Astana or Sochi," NTV quoted Erdogan as saying.
Speaking to reporters on his flight back from Senegal, he said Turkey, which is building houses in northern Idlib to shelter civilians fleeing the bombing, has told Russia that it is running out patience.
"If we are loyal partners with Russia on this, they have to put forth their stance... Our wish is that Russia immediately makes the necessary warnings to the regime which it sees as a friend," he said.
"The Astana process has fallen into silence now. We need to look at what Turkey, Russia and Iran can do to revive the Astana process," he said.
Similar comments by Erdogan (might have actually been the same as the ones right above given the date, but with a different translation)
“Russia unfortunately isn’t loyal to Astana or Sochi,” he told journalists in reference to de-escalation agreements made in the two cities.
“There is no Astana process anymore. We are losing our patience in Idlib. [Russia] either stops the bombings in Idlib or we will take the necessary [steps].”
It's not clear to me that Russia actually signed up to stop Assad's troop from advancing in some document, so it was probably just how Erdogan interpreted their spirit...
Interestingly lower-level Turkish officials didn't express the same level of faith in Russia:
“We would always know that Russia wouldn’t uphold the ceasefires,” a Turkish official familiar with the issue told Middle East Eye.
“But at the least, Russia would stop the attacks for a week or two for the pretence. Now, they declare a ceasefire on Monday and continue their attacks on Wednesday.”
And not exactly about Idlib, but since Erdogan mentioned "Sochi" too, lower-level Turkish officials claim that the Kurdish SDF have not withdrawn and now blame Russia for this...
“They only replaced border guards with Assad's forces. That’s it,” a third Turkish official said. “Russians don’t even call on them to withdraw. They are in Kobane, in Manbij, they are still everywhere.”