5 sourced reports, with what to check before you buy. Each one links to the page it was reported on.
Costly or dangerous
One UI 9 update causes heavy battery drain on Galaxy S25 series
This finding came from the query 'Samsung Galaxy S25 battery drain overheating issue'. Owners on Reddit and Samsung Community report needing to charge the S25 3–4 times a day after the One UI 9 (Android 17) update, with idle drain also reported. The same pattern is corroborated in Turkish (webtekno, teknoblog) and German (winfuture) coverage of the same update.
What to check. If you buy an S25, expect that a major OS update may temporarily wreck battery life; the fix reported is a reboot, force-stopping rogue apps, or a factory reset. It is not a hardware defect, so it should not be the reason to reject the phone.
Access Denied setup error after One UI 9 on Galaxy S25 series
This finding came from the query 'Samsung Galaxy S25 Probleme'. After the One UI 9 update, users of the Galaxy S24/S25/S26 series and foldables report an 'Access Denied' XML error during device setup; the workaround is to go offline (airplane mode or safe mode). Samsung confirmed related setup-screen freezes but not this specific error.
What to check. If an S25 shows an 'Access Denied' error during initial setup after an update, put it in airplane mode or safe mode to bypass it — the device is not permanently bricked. This is an update rollout issue, not a reason to avoid the phone.
Galaxy S25 Ultra stuck in boot loop after One UI 8.5 update
This finding came from the query 'Samsung Galaxy S25 bootloop frozen screen problem'. An owner reports the S25 Ultra getting stuck in a 'phone is starting' loop after the One UI 8.5 update, unable to enter the PIN or factory reset. This is a single owner report on a repair forum, so it is anecdotal but a genuine user-reported failure mode.
What to check. If an S25 gets stuck in a boot loop after an update, the standard recovery is a force restart (Volume Down + Power), booting to Safe Mode, or wiping the cache partition; a factory reset is the last resort. Back up data before updating.
July 2026 One UI 8.5 update causes battery drain and overheating on Galaxy S25 series
This finding came from the query 'Samsung Galaxy S25 battery drain overheating issue'. An earlier 2026 update (One UI 8.5) also produced battery drain and overheating on the S25 series; the traced culprit was WhatsApp getting stuck in its encrypted backup loop, confirmed by users canceling the backup.
What to check. If an S25 runs hot and drains fast after an update, check WhatsApp's chat backup settings first before assuming a hardware fault — canceling the stuck backup restored normal battery life for several users.
Green vertical line on OLED display reported on Galaxy S25 series
This finding came from the query 'Samsung Galaxy S25 green line display issue'. The vertical green line is a known OLED hardware failure pattern (bad solder, weak connector, panel defect) that has historically hit Samsung S20/S21/S22 series; the S25 is cited only as the current generation where the phenomenon persists, not as a uniquely affected model.
What to check. This is a general OLED risk rather than an S25-specific defect. If a green line appears, it is a physical panel fault requiring screen replacement — not a software fix — and is typically covered by warranty if it appears early.
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 Smartphones catalog, version 0.1.1, under the CC-BY-SA-4.0 license.
