Performance regression in Develop module with AI masks

ince upgrading to Lightroom Classic 15.x (currently tested up to 15.1.1), I’m experiencing severe performance degradation in the Develop module, specifically when switching between photos.

Symptoms:

• 0.5–2 seconds freeze when moving from one image to another in Develop

• Happens even with previews already built

• Occurs regardless of GPU acceleration being ON or OFF

• More noticeable when photos contain AI masks (Subject, Sky, People, etc.)

Important details:

• This does not happen (or happens far less) in earlier versions

• Hardware is more than sufficient (Ryzen 7 5700X, RTX GPU, 48GB RAM)

• RAW files are ~24MP

• Catalog stored on SSD

Tests already done:

• GPU completely disabled → no improvement

• GPU enabled only for display → no improvement

• All previews generated → no improvement

• Downgrade → only ~20% improvement

This strongly suggests a regression in the Develop pipeline, likely related to AI mask re-evaluation when switching images.
 

There are multiple reports from other users describing the exact same behavior, which indicates this is not an isolated system issue.

Question to Adobe team:

• Is this a known issue internally?

• Is there an active fix in development?

• Can you confirm whether this will be addressed in an upcoming 15.x update?

At the moment, this issue significantly impacts professional workflows and makes Lightroom Classic unreliable for high-volume editing.

Thank you — any official clarification would be greatly appreciated.