@libreoffice I downloaded the Android apk and tried it. As the fallback font and the default font of the app is Noto Naskh Arabic, which is right-to-left writing language, Myanmar Unicode Rendering went wrong.
Myanmar Unicode is a right-to-left writing abugida. Not only this app but also the latest version of Collabora Office for Android has this bug or problem. Please remember that on Android, we don't have Control+A to select all and change to Noto Serif Myanmar easily. Please reuse Liberation Serif as the default and fallback font.
I think it's pharmacokinetic side-effect of oil-producing Arabic-cetered developing to counter BRICs.