One earbud has no sound when paired — acknowledged by Xiaomi
Xiaomi's own FAQ confirms one-side sound loss as a recognized issue, listing poor contact, low battery, dirt, moisture short-circuit and Bluetooth disconnection as causes.
What to check. One-side sound loss is acknowledged by the maker; the listed fixes are cleaning, re-pairing and a 10-second factory reset, otherwise service center.
These reports come from the pages linked under each item: owner forums, repair guides and workshops. They are not a diagnosis of any one unit, and a careful check of the one you are buying still applies.
Text from the Kriko Wireless earbuds catalog, version 0.1.4, under the CC-BY-SA-4.0 license.