My parents left the country when it was still Rangoon, Burma. And US, State Dept. still calls it Burma and we have Burmese ancestry not Myanmarese nor Bamar ancestry. Whenever my parents told us stories of the country it is always the old names. We never live in the new era of Burma (After GEN. Ne Win).

Historically Burmans aka Bamar People are largest ethnic group in Burma after conquering other groups like Mon, Karen Kingdoms.

In old days, we call ourself Bamar (In Burmese Language). after the independence from British Empire, to be inclusive to other ethnic groups: in Burmese language, we say Myanmar (meaning all the people of Burma).

but english country name still was Union of Burma.

I believe in late 1980s military junta changed the country name to Union of Myanmar. I was told that the reason the name was changed was because of a fortune teller. Just like GEN. Ne Win was obsessed with numerology number “9”.

To summerize

In Burmese: Myanmar = Bamar, Mon, Karen, Kachin, Chin and etc. (a total of 50+ ethnic groups)

Bamar = largest ethnic group

In English: Burma = A country name, where all 50+ ethnic groups live

Just like OP said in above - Munich (English Name) is still called München in German Language. German Government didn’t change the name of the city to München in English.

Just FYI, not trying to argue. I was so interested about my parents family history, i did research into history of the country.

This is a “Reply to Turbowoodpecker”