6 sourced reports, with what to check before you buy. Each one links to the page it was reported on.
Costly or dangerous
Left earbud battery dies in ~5 minutes after ~8 months of use (TR)
An owner reports the left earbud's charge now lasts only about 5 minutes after roughly 8 months of normal use.
What to check. Expect the left earbud battery to degrade sharply within the first year; if it dies in minutes, the unit is effectively unusable and needs replacement rather than a fix.
Left earbud produces no sound despite holding charge (EU/Greece)
From the Skroutz.eu product discussion (EU market). An owner reports the left earbud made no sound even though it had charge and the app recognized it as the left side, after resetting via Bluetooth and the app.
What to check. One-side no-sound is a recurring failure mode; if resetting does not restore it, the earbud is defective and should be returned or warrantied rather than accepted.
Disconnects and goes silent when taken out of the case (Windows)
From a Microsoft Q&A thread (Windows 11 laptop). The buds pair and appear connected, but produce no sound and drop the link shortly after being removed from the case; the poster says all suggested steps failed.
What to check. If you use these with a Windows PC, expect possible silent/disconnect behavior on removal from the case; it may not be fixable by the user.
Official Xiaomi FAQ acknowledges left/right power imbalance and non-replaceable battery (EU/NL)
From Xiaomi's official Dutch FAQ for REDMI Buds 5. Xiaomi states that when one side is not worn properly in noise-cancelling mode, a large difference in power level between left and right earbuds will occur; it also states the battery cannot be replaced.
What to check. The L/R power gap is partly acknowledged by the maker and the battery is not user-replaceable, so battery degradation means a new unit rather than a repair.
Repeated connect/disconnect loop on Pixel 7 after Android 15 (EU/ES)
From a Google Pixel support thread (Spanish, model M2316E1). After updating to Android 15, the buds connect then disconnect in a loop on the user's Pixel 7, while working fine on other phones.
What to check. Compatibility with some Android phones is inconsistent; if you hit a connect/disconnect loop, try another device before assuming the buds are faulty.
Runtime far below advertised: ~2h50m vs claimed 6.5h (TR)
From the same Şikayetvar page (TR market). A buyer reports the earbuds run out after about 2 hours 50 minutes, versus the 6.5 hours stated on the site.
What to check. Do not rely on the advertised playtime; a new unit may deliver roughly half the claimed runtime, so budget for frequent case recharges.
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.