Updating your Samsung device to the latest firmware can enhance performance and unlock new features, such as One UI 8. This guide covers flashing the AYC3 and AY28-5 firmware, including step-by-step instructions for using Odin and sideloading updates. Follow these steps to safely update to AYC3 (XNZ) or AYDA firmware

You need to be on AYC3, it looks like XNZ is the only AYC3 firmware currently available. You can flash this using Odin, make sure you use Home_CSC, keeping data,a just change your CSC back after flashing, then you can sideload BYDD.

XNZ – New Zealand  Samfw link

csc_information=OXM(ACR AFG AFR BKD BNG BOG CAC CAU CPW DKR ECT EGY EUX EUY FWD GLB ILO ILP INS KSA LYS MEO MET MID MM1 MOB MOT MSR MWD NPB OPS PAK PKD PLS PRT SER SFR SIM SIN SKZ SLK SOZ STH SWC TEL THL TOP TUN TUR VAU VIP WWA WWC WWD XFA XFV XME XNZ XSA XSG XSP XTC XXV XID)

One UI8 test firmware

Download and Sideload the firmware

Google Drive link AYC3 – BYDD

Credit to Igor 

Please see Page 3 for known issues @Rapier has found.

New update:

Flash stable AYD9 with Odin

Then you can update to

AYD9 – BYE2 <<– download link

Credits @Belco02 and @ashutosh28

The first unofficial beta test firmware must be on the AYDA OXM firmware to flash the beta

csc_information=OXM(ACR AFG AFR BKD BNG BOG CAC CAU CPW DKR ECT EGY EUX EUY FWD GLB ILO ILP INS KSA LYS MEO MET MID MM1 MOB MOT MSR MWD NPB OPS PAK PKD PLS PRT SER SFR SIM SIN SKZ SLK SOZ STH SWC TEL THL TOP TUN TUR VAU VIP WWA WWC WWD XFA XFV XME XNZ XSA XSG XSP XTC XXV XID)

S938B
Download Link AYDA – ZYEA (Credit to @seba84_2005)

Official Beta is rumored to start in about 3 weeks.

Early Impressions & Bugs – Samsung Galaxy S25 Ultra

1. Random Reboot

• Experienced a one-time unexpected reboot while in the Settings menu. The issue has not recurred.

2. VoLTE / 4G Connectivity Issue

• When VoLTE/4G is enabled, incoming and outgoing calls fail. Incoming calls get disconnected on the caller’s end with a tone and no error message.
• Disabling VoLTE/4G resolves the issue.
• VoWiFi works without issues.

3. eSIM Recheck Prompt

• After reboot, the device prompts to recheck the eSIM. Unclear if this is intended behavior or a bug.

4. Google Wallet & Banking Apps Compatibility

• Google Wallet reports that the device does not meet security requirements, hence it won’t work.
• This was expected due to early software. Banking apps and Samsung Wallet likely won’t work either.

5. Good Lock Compatibility

• QuickStar is currently not compatible. Other Good Lock modules may also be affected.

6. Secure Folder Fingerprint & PIN Bug

• Secure Folder now asks for separate fingerprint registration, possibly a new feature.
• Bug: PIN is reported as incorrect when attempting to access the Secure Folder, even when the correct PIN is entered.
• Suspected cause: mismatch between device PIN (4-digit) and Secure Folder PIN (6-digit).
• Workaround: Save the Secure Folder PIN somewhere and copy-paste it into the PIN entry field.

7. Missing Settings Compared to YouTube Previews

• Some settings showcased on YouTube (possibly from the Flip) are not available on the S25 Ultra.
  • Example: “Even Dimmer” brightness option.
  • Forcing dark theme on all apps via Developer Options is still present.

8. Weather App Revamp

• The Weather app has a new interface and updated animations.

9. Contacts UI Update

• Adding a new contact now shows an updated interface.
• You can directly edit/add the Profile Card.

10. Settings Search Functionality

• The Settings app no longer supports natural language search. It has reverted to a basic keyword-based search.

11. Navigation Bar Issues

• When using gesture navigation, the central home gesture hint is missing or non-functional.
• With button navigation enabled, only the back button appears.
• Restarting the phone restores normal functionality.
• Disabling NavStar and One Hand Operation+ does not resolve the issue.

12. Refined UI & Visual Enhancements

• Several UI elements now appear more refined with added translucency in Gallery pop-ups and system menus.
• Quick Settings background has increased transparency.

13. Battery Charging Animation

• New charging animation in the status bar, resembling the one introduced in the One UI 7.0 April security patch (AYD9).

14. Notification Pill Visual Update

• Notification indicators on both lockscreen and Quick Settings pulldown are now blurred for a modern look.

development