Presets issue, not showing in folders after update but in the correct folders on the computer/

Hi Adobe Support,

Since updating to Lightroom Classic 15.4.1, a large number of my Develop presets have disappeared from the Presets panel.

My system

• Lightroom Classic: 15.4.1
• Camera Raw: 18.4
• macOS: 26.5.2
• iMac 2020
• Same Lightroom catalog I've been using all year (2026.lrcat).

The issue

• After updating Lightroom, I was away for a week.
• When I returned, many of my presets were missing.
• The preset files (.xmp) are still present in the correct Settings folder.
• If I try to import a missing preset, Lightroom reports "Already Imported", but the preset still does not appear in the Presets panel.
• Some presets from the same collection are visible, while many others are not.

Troubleshooting already completed

• Confirmed I am opening the correct catalog.
• Created a brand new test catalog – the exact same presets are still missing.
• Verified the preset files exist in:
  • Catalog Lightroom Settings folder.
  • CameraRaw Settings folder.
• "Store presets with this catalog" has been tested.
• Checked Manage Presets – the missing presets are not hidden.
• The missing presets cannot be imported because Lightroom reports they are already imported.

Additional information

• Existing photos edited before the update still contain the preset in their History panel.
• Clicking a history step such as PNW EDIT BUMP correctly reapplies the edit.
• This indicates the preset data still exists and Lightroom can still render it on existing edits.
• However, many of those presets no longer appear in the Presets panel for use on new images.

Preset collection affected

The presets are from Reverie + Oak / Pacific Northwest Presets.

Could you please advise whether this is a known issue with Lightroom Classic 15.4.1 or if there is a way to force Lightroom to rebuild its Develop Preset index/database without losing my catalog or edits?

Thank you.