To the long time observers in the region it is well known that China has long been supplying weapons to the guerillas operating in Myanmar since after WWII. There is a long history of China's active involvement in Burma which started with Communist Party of Burma (wiki link provided). China trained the communist guerillas of Burma. Once Communist Party of Burma (CPB) collapsed into its ethnic factions, their relationship with Beijing continued. The largest private armed organization or faction that broke off from CPB is the United Wa State Army with a standing count of 30,000 soldiers, the world's largest private army - as big or bigger than armed forces of some countries including Sweden, Belgium, Georgia, Portugal. China sent an OFFICIAL representative to Wa State Army parade as an indication of how close the relationship is.[https://www.scmp.com/news/asia/southeast-asia/article/3006575/masters-our-destiny-myanmars-25000-united-wa-state-army]. Well known defense magazine Janes Weekly wrote an article of Chinese military equipment on display at the parade [https://www.janes.com/defence-news/news-detail/united-wa-state-army-military-parade-showcases-ongoing-modernisation#:~:text=Other%20modern%20Chinese%20infantry%20weapon,mounted%2012.7%20mm%20QJZ89%20heavy]. Interestingly, the official currency and language in Wa State is the Yuan and Mandarin.

Recently in 2021, China has resuscitated Communist Party of Burma and its military wing People Liberation Army and they are active once again.

Article stating Indian government suspects Chinese helping guerilla groups on its border with Myanmar, outlining Beijing's links to the guerilla armies in Myanmar: [https://timesofindia.indiatimes.com/india/china-helping-rebel-groups-on-myanmar-border-india/articleshow/79601798.cms]

China also has been the main supplier of arms to Burmese military for decades. In the last 10 years under current Junta boss Min Aung Hlaing who was formerly the chief of staff of armed forces, Burmese military has complained of the reliability issues with Chinese weapons and have begun to seek alternative sources elsewhere - mainly Russia, but also India. Here are articles indicating who's arming the illegitimate Junta in Myanmar: [(https://www.aljazeera.com/news/2017/9/16/who-is-selling-weapons-to-myanmar)] [https://apnews.com/article/myanmar-weapons-russia-china-singapore-05bd26bc54df8bc682ee1143f0f36a5e]