This is what I have heard of CR929 program. Before 2020, China agreed to build CR929 for Chinese market, while Russia has the rest of the world which is big. However, the sanction since 2020 means that Russian airlines CR929 can not fly over EU and US, also UAC can not maintain and service any Russian made CR929 in EU and US even though the aircraft belongs to a third country (for example Kazakhstan) because no Russian made components can be imported to EU and US. This severely reduced the desire of buying CR929 from UAC. Therefor, the promised Russian share of the market shrunk drastically. Most possible orders will be turned to China, even Russian designed/produced components have to go through China somehow to bypass sanctions.
Russia may have asked China to revise the agreement (hence the romours), that is China to give Russia a large chunk of Chinese market, while China takes over the "rest of world" share. However, China is reluctant because China's market is garanteed, but outside isn't especially routes ending in EU and US who will resist letting in CR929 even without any sanctions. So there is not much interest left for UAC to stay as partner.
So I think the Russian dropping out is caused by Western sanctions, but it isn't because China cares much about western countries feeling , demand and threat as many people suggest. China only cares about her own aviation industry being self-reliance and successful.
Russia may have asked China to revise the agreement (hence the romours), that is China to give Russia a large chunk of Chinese market, while China takes over the "rest of world" share. However, China is reluctant because China's market is garanteed, but outside isn't especially routes ending in EU and US who will resist letting in CR929 even without any sanctions. So there is not much interest left for UAC to stay as partner.
So I think the Russian dropping out is caused by Western sanctions, but it isn't because China cares much about western countries feeling , demand and threat as many people suggest. China only cares about her own aviation industry being self-reliance and successful.