6 sourced reports, with what to check before you buy. Each one links to the page it was reported on.
Costly or dangerous
Xiaomi Pad 6 Wi-Fi fails on some units despite resets and cable fixes
A Polish review aggregation reports that on some units Wi-Fi does not work at all, even after resetting settings or installing fixes via cable. This is a hardware-level connectivity failure that would require service or replacement.
What to check. If buying, verify Wi-Fi works immediately on the unit you receive; if it fails, return it rather than attempting software fixes.
Xiaomi Pad 6 apps stop opening after a post-warranty update (TR market)
A Turkish owner reports that after the warranty expired, a system update caused apps (Disney+, Tod, HBO) to stop opening, and the authorized service center returned the tablet with the issue unresolved.
What to check. A post-warranty software update can break app compatibility; the service center did not fix it. Consider delaying major updates or checking forums before installing them.
Xiaomi Pad 6 switches off when launching apps, requires cache clear or restart
A Netherlands-based verified buyer on Back Market reports the tablet randomly switches off when launching apps (YouTube, Google Earth), requiring a restart or cache clear each time.
What to check. Random shutdowns on app launch are disruptive and recurring; only cache clearing or restart helps. This is a software-level issue, not a hardware failure.
Xiaomi Pad 6 Bluetooth audio playback lags when a Bluetooth device is connected
XDA forum users report that connecting a Bluetooth audio device causes media playback to lag with no audio, even after disabling Google Assistant features and doing a clean wipe.
What to check. Bluetooth audio lag persists even after clean wipes and disabling assistant features; this is a known software-level issue on the Pad 6.
Xiaomi Pad 6 lags and freezes when online after about a year of use
A Yandex Market owner review reports that after a year, the tablet starts to lag and freeze when connected to the internet.
What to check. Expect possible performance degradation after a year of use, especially when online; this may be mitigated by clearing cache or factory reset.
Xiaomi Pad 6 restart takes up to 5 minutes, stuck on Mi logo
XDA forum users report restarts taking up to 5 minutes stuck on the Mi logo; a factory reset improved boot speed but did not fix battery health features.
What to check. Slow boots can be improved with a factory reset, but battery health features may remain broken. This affects daily usability.
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 Tablets catalog, version 0.1.1, under the CC-BY-SA-4.0 license.