INSTALL_FAILED_UPDATE_INCOMPATIBLE despite matching signatures for com.google.android.gsf

I'm attempting to reinstall com.google.android.gsf (Google Services Framework) on my Android device using ADB, but I keep encountering this error:

adb: failed to install com.google.android.gsf_15-35_minAPI35(nodpi)_apkmirror.com.apk: Failure [INSTALL_FAILED_UPDATE_INCOMPATIBLE: Existing package com.google.android.gsf signatures do not match newer version; ignoring!]

Interestingly, when I verify the signatures of both the new APK and the existing APK on the device using apksigner verify --print-certs, they are identical. Here are the details:

(base) PS C:\Users\x> apksigner verify --print-certs "D:\x\Downloads\com.google.android.gsf_15-35_minAPI35(nodpi)_apkmirror.com.apk"
Signer #1 certificate DN: CN=Android, OU=Android, O=Google Inc., L=Mountain View, ST=California, C=US
Signer #1 certificate SHA-256 digest: 7ce83c1b71f3d572fed04c8d40c5cb10ff75e6d87d9df6fbd53f0468c2905053
Signer #1 certificate SHA-1 digest: bd32424203e0fb25f36b57e5aa356f9bdd1da998
Signer #1 certificate MD5 digest: f026fdcf21375f987164c84da76ef5fd
Source Stamp Signer certificate DN: CN=Android, OU=Android, O=Google Inc., L=Mountain View, ST=California, C=US
Source Stamp Signer certificate SHA-256 digest: 3257d599a49d2c961a471ca9843f59d341a405884583fc087df4237b733bbd6d
Source Stamp Signer certificate SHA-1 digest: b1af3a0bf998aeede1a8716a539e5a59da1d86d6
Source Stamp Signer certificate MD5 digest: 577b8a9fbc7e308321aec6411169d2fb

(base) PS C:\Users\x> adb shell "pm list packages | grep gsf"
package:com.google.android.gsf
(base) PS C:\Users\x> adb shell "pm path com.google.android.gsf"
package:/data/app/~~XUohexMH35YRG11Tz5anTA==/com.google.android.gsf-9p6W7xLYfLz3hewFtmEMVw==/base.apk
(base) PS C:\Users\x> adb pull /data/app/~~XUohexMH35YRG11Tz5anTA==/com.google.android.gsf-9p6W7xLYfLz3hewFtmEMVw==/base.apk
/data/app/~~XUohexMH35YRG11Tz5anTA==/com.google.android.gs...ile pulled, 0 skipped. 33.6 MB/s (4165872 bytes in 0.118s)
(base) PS C:\Users\x> apksigner verify --print-certs .\base.apk
Signer #1 certificate DN: CN=Android, OU=Android, O=Google Inc., L=Mountain View, ST=California, C=US
Signer #1 certificate SHA-256 digest: 7ce83c1b71f3d572fed04c8d40c5cb10ff75e6d87d9df6fbd53f0468c2905053
Signer #1 certificate SHA-1 digest: bd32424203e0fb25f36b57e5aa356f9bdd1da998
Signer #1 certificate MD5 digest: f026fdcf21375f987164c84da76ef5fd
Source Stamp Signer certificate DN: CN=Android, OU=Android, O=Google Inc., L=Mountain View, ST=California, C=US
Source Stamp Signer certificate SHA-256 digest: 3257d599a49d2c961a471ca9843f59d341a405884583fc087df4237b733bbd6d
Source Stamp Signer certificate SHA-1 digest: b1af3a0bf998aeede1a8716a539e5a59da1d86d6
Source Stamp Signer certificate MD5 digest: 577b8a9fbc7e308321aec6411169d2fb

Note: The pm list packages command does not display hidden system packages, so it only shows the user-installed or updated version of com.google.android.gsf. To see all instances, I used dumpsys package packages | grep -E "Package \[|versionName=" | paste - - | grep gsf, which revealed two instances: - Package [com.google.android.gsf] (ec252b0): versionName=15 (user-installed or updated version) - Package [com.google.android.gsf] (248eb70): versionName=15-11962157 (hidden system package, codePath=/system_ext/priv-app/GoogleServicesFramework) I suspect the hidden system package might be interfering, but since the signatures of the new APK match the user-installed version, I’m puzzled about why the installation fails. #### What I've Tried: 1. Ran adb install -r -d to allow downgrading, but the same error occurs. 2. Cleared the package data with adb shell pm clear com.google.android.gsf, yet the issue persists. 3. Confirmed the device is not rooted, so I can not just uninstall the package and reinstall it. #### Questions: 1. Why does the installation fail with a signature mismatch error when the signatures of the new APK and existing user-installed APK match? 2. Could the hidden system package be causing this? 3. Are there other factors—like version codes or system protections for com.google.android.gsf—that I should investigate? Any help or suggestions to successfully install the APK would be greatly appreciated! #### Additional Details: - **Device**: Vivo X100 Ultra - **Android Version**: Android 15 - The APK is sourced from APKMirror.