How to fix Touch ID issues after macOS Sequoia 15.5 update?

Predicated on user byline " iMac 24″, macOS 15.5 "

This computer would be using an External Touch ID Keyboard from Apple

One similar to Magic Keyboard with Touch ID and Numeric Keypad for Mac models with Apple silicon (USB‑C) -

Suggest cabling the Keyboard directly to the computer

Make sure to use the slider on the front edge of the keyboard to ON

This would effectively make the keyboard act like a USB connected keyboard

Does the Touch ID function ??

If Not - the keyboard maybe defective

I won't be surprised if the regression only happens on older machines like mine. It is highly unlikely that the keyboard/sensor is defective if it was working just before the upgrade. To verify, it is quite easy to install another, older version of macOS such as 15.4 on an external SSD and boot the machine off of that. If Touch ID works there, then it is clearly a regression in 15.5, which is the case on my machine. I cannot even re-enrol my fingerprints after deleting them because the Touch ID sensor is not responsive under 15.5.

I have had no such issues. Have you tried setting it up again by removing fingerprints and adding again?

I was talking about installing a fresh, clean copy of an older version of macOS on an external SSD to verify that the Touch ID hardware was working. This is a separate installation and does not touch the existing macOS 15.5 installation on internal SSD.

It is worth trying again in a few days after the system has settled down. It started working again on my old 2018 Macbook Pro. It is possible that immediately after the upgrade, some background tasks (e.g. Spotlight indexing the filesystem) were interfering with the Touch ID functionality, especially on older hardware.

I had no such issue updating my Macs to Sequoia 15.5. I would try recreating your Touch ID as muguy suggested.

I just upgraded to build 24F74 and am having the same issue on my Macbook Pro, MacBookPro17,1 with an M1 processor. Annoyed!

Same here, Touch ID stopped working after upgrading to Sequoia 15.5 on a late 2018 Macbook Pro 15.

No issue with touch id here, running 15.5 on an M4 Pro MBP.

+1 on the suggestion by muguy

Regression to older version of Sequoia maybe possible but not officially supported

Yes. Didn't know what else to try; but unfortunately, it didn't correct the problem.

was your macbook plugged in while you were trying by any chance?