ACR 16 different color compared to PS, LR after increasing bit depth to 32 in HDR mode

I've had a similar issue in April '23, with ACR showing oversaturated colors compared to PS/LR when HDR Output in Tech Previews was enabled. Disabling would help, but then of course HDR editing would no longer be possible. After a few Adobe updates, this issue went away by itself. I am mentioning this because I assume my current problem is related.

Current problem:

Having HDR display on, opening an image in ACR looks different (oversaturated) to PS IF: image has been changed to 32 bit before (necessary for HDR editing); this happens for RAW files as well as edited TIF files and even JPGs. However, it only happens on my external monitor, NOT on the internal laptop monitor

Already tried:

• Deactivate GPU in preferences/performance: no effect
• Deactivate GPU in file handling/ACR/performance: no effect
• Deactivate Native Canvas in preferences/tech previews: no effect
• Deactivate HDR Defaults in ACR Preferences: no effect
• Deactivate HDR on external monitor: PS and ACR match!
  For 0.5 seconds when opening ACR, it shows oversaturation before switching to standard colors, as if a setting needs to be fully loaded first before displaying colors properly. This might or might not be an indicator for a SW issue.

To check how LR is behaving, I did a Library vs. Develop mode test both on the same RAW and edited TIF file (RAW is totally untouched, TIF only SDR-edited and no bit increase to 32 applied)

• HDR activated on monitor: color mismatch Library/Develop (more saturated in Develop)
• HDR not activated on monitor: Library/Develop match

Running Adobe Photoshop Version: 25.0.0 20230906.r.37 b14e317  x64 on Win11 64bit Laptop, NVIDIA GeForce RTX 3060 Laptop GPU

ACR: 16.0.0.1677

This mismatch currently blocks me from doing any HDR editing, since I cannot rely on color consistency. Any advice would be much appreciated. I've attached a few screenshot to better illustrate the mismatch.