Unlike India or China. Junta is not a recognised government of MM. Chinese took action because it's affecting them. Not for the larger good of MM. Trying to project it as some show that China is against Junta is childish.
You need a historical perspective to understand China's position in Burma.
1, The main ethnic group in Burma is the Burmese, who are divided into two camps, the military junta and the MNDAA (Aung San Suu Kyi). These two camps are hostile to each other, but all their values are ultra-nationalist, so whoever comes to power will oppress the Rohingya.
The Burmese, who make up less than 50% of Myanmar's population, collectively have a strong sense of insecurity and they hate all ethnic minorities. So there are only nationalist parties within the Burmese community, no exceptions. But the ethnic warlords in the north are difficult to deal with, so any Burmese ruling party will channel the hatred of the people towards the Rohingya. This is what the Rohingya are facing.
The Rohingya problem stems from the deep-seated fear of the main body of the Burmese nation. No country can solve this problem, including China. The Chinese Government can only try to mediate, which is one of China's positions.
2, The ancestors of the Burmese are the White Wolf Qiang tribe in China. In the seventh century A.D., when the Chinese emperor expelled the White Wolf Qiang, the White Wolf Qiang fled from China's Yunnan Province to Burma, where they became the new dominant ethnic group in the country by overthrowing the local Mon regime. The armies of the various ethnic groups sent by the Chinese Emperor to hunt down the White Wolf Qiang were entrenched in the northern part of Burma, and eventually became local lords loyal to the rival Burmese in China. Eventually various Burmese lords, including the Burmese regime, became bannermen of the Chinese Emperor.
More than a thousand years have passed, and the Chinese imperial dynasty has been extremely influential in Burma as a result of the continued arrival of exiled Chinese to the country and the gradual sinicization of the culture here. But these lords fought each other and their hatred grew deeper and deeper. Successive Chinese governments only had the power to mobilize their armies, but not the power to defuse the hatred between them. Just as the United States is now powerless to defuse the hatred between Korea and Japan, Greece and Turkey.
The same goes for the current Chinese government. There are no forces in Burma that oppose China, but neither does China have the ability to control them completely. The force that China has been supporting is Wa, which also has the strongest military power in Burma. Secondly China supports the Three Brothers Alliance and MNDAA through Wa to attack the junta. The junta has angered China on issues such as telecom fraud (China views telecom fraudulent behavior in the Mandarin-speaking community as a provocation to China's core circle of interests) and China wants to punish them. The junta is trying to curry favor with China and they know that China has the power to completely destroy them. The junta's recent moves such as handing over the Deputy Minister of Defense to China and leasing Kyaukpyu to the Chinese military for 99 years are all efforts to calm China's anger. But the fact that the Three Brothers Alliance's attacks on the junta have still not stopped shows that the Chinese government's anger has not gone away.
So China's position in northern Burma is that China has the ability to mobilize these warlords to attack a certain power through various means, but China doesn't have the ability to stop them from attacking each other. And the hatred between them has been building up for thousands of years, and it's not going to dissipate that easily.
3, Myanmar's junta and MNDAA don't actually like the Chinese, but they are afraid of them. China's influence over Burma has been going on for thousands of years, and it's the one country that actually has the power to completely overthrow Burma. Any Burmese ruling party is bound to work hard to gain China's support and approval. Of course, the incident of the junta coercing the Chinese government to recognize the legitimacy of the junta by interrupting the B&R project is one of the main reasons for angering China.
China's position on the Burmese regime remains that it recognizes only the legitimacy of Daw Aung San Suu Kyi and not the military government. Incidentally, the only major power that recognizes the junta is Russia, not China.
Map of the territorial distribution of Burma during the rule of the ancient Chinese lords:
