P: .MTS video and audio not synched on Mac OS and Adobe 24

Issue: No audio is detected on my MTS video (with audio) clips loaded into Premiere Pro 25, After Effects 2025 and Media Encoder 2025.

HP Z2 G9 workstation
Intel(R) Core(TM) i7-14700 2.10 GHz
64.0 GB RAM

Nvidia RTX A2000 12 GB
driver 552.34

Windows 11 Pro
version 24H2
OS build 26100.2161

HP M2 (boot) C drive
Crucial M2 D and E drives (holding video clips)

Adobe CC licensed version 6.4.0.361
Premiere 25.0
After Effects 2025
Media Encoder 2025

.MTS format clips are AVCHD H.264 4:2:0 MPEG movie, 48000 Hz compressed stereo from a Sony PXW-Z100 camera

Background: To replace a near-obsolete computer running Windows 10 Pro with Premiere 23.6.8, I recently purchased a brand new HP Z2 G9 workstation computer as configured above. Before loading any software, I did all Windows updates. I then loaded VideoLan VLC video player, Sony Catalyst Browse, Vegas DVD Architect and then my licensed Creative Cloud followed by a half dozen CC apps, including Premiere Pro 25. After transferring my Premiere Pro projects and media from my older computer to my new computer, using the same directory paths for files.

1) I open any of my projects in Premiere 25.0 and only the MTS format video clips return an error message of "MEDIA MISMATCH. The selected file does not contain audio media used by clip references in one or more sequences. These audio clip references will be deleted, and cannot be undone. Do you want to continue?"
2) If I hit OK to continue, the MTS video clips load, but with no audio.
3) If I hit Cancel, the MTS clips remain offline, but with their properties showing that they are both video and audio.
4) If I then select the offline MTS clips, go to Link, and then Locate, the clips also load without audio or an audio reference.
5) I close the project. Within Premiere, I choose the option to clean all cache files.
6) I manually go to both C:\Users\Public\Documents and to C:\Users\AlanS\AppData\Roaming\Adobe\Common and delete Adobe cache and media cache files.
7) I try opening a different project with MTS clips and get the same result where audio is not recognized.
😎 I reinstalled Premiere 23.6 and get the same result where audio from MTS clips is not recognized.
9) I uninstalled all Adobe apps and Creative Cloud, cleaned the caches, reinstalled CC and the apps and got the same result where audio from MTS clips is not recognized.

As an additional test, I created a new Premiere 25.0 project.
1) I manually go to both C:\Users\Public\Documents and to C:\Users\AlanS\AppData\Roaming\Adobe\Common and delete Adobe cache and media cache files.
2) I Start Premiere while holding shift key to clear cache
3) I create new project.
4) I import .MTS clips
5) MTS clips load as video only, with no audio or audio reference

This problem occurs with old or new MTS clips in old or new Premiere Pro 25.0 or 23.6.8 projects. All other video formats such as mp4, mpg, mov, and mxf load properly with associated audio. My suspicion is there is an issue with these brand new versions of CC apps along with the brand new Windows 24H2 build. I am not able to roll back my version of Windows.

Meanwhile, on both my aging workstation running Windows 10 Pro with Premiere 23.6.9 and my backup computer running Windows 11 Home and Premiere 25.0 the MTS clips correctly load with both video and audio.