The Mi A3 has had a rough ride of it lately. While Xiaomi may have started issuing a new beta Android 10 build to some handsets, the company is yet to address the mess that it rolled out publicly just over a week ago. However, that may be on the verge of changing.
Brought to our attention by Piunikaweb, Xiaomi support has been screenshotted as claiming that a new build "may [be] rolled out [at the] end of this month". While support representatives are not always accurate about the timing and release of software updates, it is encouraging to see that news of a new update has filtered down to them.
Until then, we would recommend sitting tight on whatever version of Android on which your Mi A3 is currently running. Trying to roll back to Android 9.0 Pie from Android 10 may cause issues, not least system instability. Likewise, we would not recommend manually installing the original Android 10 build, as it contained enough bugs for Xiaomi to pull it. Additionally, there does not appear to be any download links for the latest beta build, V11.0.7.1.QGQMIXM. Alternatively, you could always try a custom ROM from XDA Developers, but these can present their own problems.
Source(s)
Reddit via Piunikaweb