The extent that Russia accepted that principle had already reached its limit by 2008, when (in the context of the 2008 NATO summit in Bucharest, which he attended), where the candidacy of Georgia and Ukraine were on the table, Putin said that
We view the appearance of a powerful military bloc on our borders, a bloc whose members are subject in part to Article 5 of the Washington Treaty, as a direct threat to the security of our country. The claim that this process is not directed against Russia will not suffice. [...]
We have eliminated bases in Cam Ranh (Vietnam) and in Cuba. We have withdrawn our troops deployed in eastern Europe, and withdrawn almost all large and heavy weapons from the European part of Russia. And what happened? A [US] base in Romania, where we are now, one in Bulgaria, an American missile defence area in Poland and the Czech Republic. That all means moving military infrastructure to our borders.
(TBH, I'm not sure what he meant by "we have [...] withdrawn almost all large and heavy weapons from the European part of Russia".) In the same speech he says that NATO's "out of area" operations (like Kosovo) cast doubt on the alliance's true goals, and complains that the (then recently admitted to NATO) Latvia didn't give citizenship to its Russian speakers.
And while this was surely not first time someone in a position of power in Russia said something like that (even Yeltsin protested the idea of a NATO expansion in the 1990s, but was more easily placated), Russia made its point in 2008 by invading Georgia, in response to the renewed clashes between Georgian armed forces and South Ossetian separatists. Later on, Medvedev (president during the seat swap with Putin) declared that the armed intervention in Georgia was essential in having prevented Georgia from joining NATO.
Some Western observers pointed out in Feb 2022 that Russia was repeating the "Georgia playbook" with Ukraine.
Yeah, someone is gonna say "but Finland, 2023". Russia would have perhaps prevented that too, if their forces were not overstretched in Ukraine. For now they've declared that Northern Europe has become "unstable":
Russia's Foreign Ministry said Moscow "will be forced to take military-technical and other retaliatory measures to counter the threats to our national security arising from Finland’s accession to NATO.”
It said Finland's move marks "a fundamental change in the situation in Northern Europe, which had previously been one of the most stable regions in the world.”
In a 2022 speech, referencing Peter the Great's campaigns (against Sweden, but also around Narva, presently in Estonia) Putin said that (similarly) "it fell to our lot to return and reinforce as well" places where "from time immemorial, the Slavs lived". Anyhow, as of 2022, Putin was drawing a finer line between NATO candidates that Russia had territorial disputes with and those without:
“We don’t have problems with Sweden and Finland like we do with Ukraine,” the Russian president told a news conference in the Turkmenistan capital of Ashgabat. “We don’t have territorial differences.”
For the latter, in late 2021, Russia demanded a return to pre-1997 armed forces deployments in Europe, so that NATO's expansion since then would be, more or less, confined to paper.
BTW, although the Q itself notes this to some extent, I should probably mention here that many European countries regard the CSCE/OSCE conference outputs as politically but not legally binding. Among the numerous principles declared in OSCE documents, Russia for instance likes and insists on the "indivisible security" one. In particular they raised it again in Feb 2022, shortly before invading Ukraine. And after the Georgia war, Medvedev proposed a European Security Treaty that would have raised the "indivisible security" principle to a legally binding status, but this was rejected by other countries, including Germany, who argued that it is too vague for such a role, and in fact (despite being in the same Istanbul declaration) rather contradictory with the freedom of countries to choose alliances:
German Minister of State Werner Hoyer noted the difficulties involved in attempting to make the principle of indivisible security into a mandatory legal requirement. “How, for example, does the concept of indivisible security fit with the freedom of countries to choose what alliances they belong to, something to which we are all committed?” he asked.
As noted by other analysts (in that paper), the 2009 Russian treaty draft in fact proposed to resolve this by making any other prior commitments subordinate to this "indivisible security" principle (via its Article 9), so essentially giving Russia, from then on, a legal veto over NATO expansion, troop deployments, etc., assuming NATO members would have signed on. Even the right to collective self-defense was made subordinate to the same "indivisible security" in this proposal. In case of being attacked, a signatory state retained the right to convene an Extraordinary Conference, where collective defense decisions had to be unanimous (minus the attacking country, if among the signatories). Needless to say that such a design favored big countries over small ones since the former could self-defend on their own, an action which did not need Conference approval.
The 1999 Istanbul joint ministerial statement even contained some rather more concrete commitments like (p. 50)
- [...] We welcome the commitment by the Russian Federation to complete withdrawal of the Russian forces from the territory of Moldova by the end of 2002.
Which, of course, has yet to happen even 20 years later, and was a bone of contention in some later OSCE summits e.g. in 2010.