Describe the bug

Using a reactive registry/object to bind refs to components rendered in an {#each} doesn't always work as expected. In the specific case captured in the reproduction, Svelte sets refs for existing components in the registry to null after the keyed {#each} block updates, even though the components aren't destroyed.

Hopefully the reproduction makes the exact issue clearer, because this is a little hard to describe. The reproduction is a bit contrived, but it does capture my original use case.

Reproduction

https://svelte.dev/playground/hello-world?version=5.55.5#H4sIAAAAAAAAE4VU226jMBD9lZE3D6BNoX3YFxZSVfsH0b6VSHGwSawaG9mTpBHi31e2IYFsL0-guZ45c8YdUbThJCNrTisUJw47oViGB2FBKOh-cFodethJXb2RJamF5JZkrx3BS-vSnIEsxyIvbZvYE5fobDtq-Uf2SivkCi3JSG4rI1pclapE0bTaIHQoqrceaqMbKElIKslvFzGJWuvzGJKka31OpoGqRMkR1LGxUMDCIkUevW5iX6TSyiIYffY-xo04cRa52KShbaSgWEHUCZaBWoKDn8HWdVt0qt_2cXxXZc3rSZOujwcA1F5UBfVRVSi0AsrYWp-jGDo_yJAvGBQQelOMHp5ieH6Gxxh-wlMYGL2vPdpDJFg82OiZCgRHUzSaBiCvgm2ek0reXH1Ac8WBRuz33Dgsgl3RfJe-EMq2vMJoCHTOPL3tTuVMnKCS1NqiJI7bkvidBvkEtql1X3A1EsHiPrTOHbeO5qJzDvfX3yTojR5ayNr0kIbCqdel-531dtoyWo79S8x3R0StQCs_V9GFTfSrF8YcnjwNAUP494A_KBnFTjQTaseM1d9gg9ts9_0mc6RMnFaO2PAtVW7xIrmPTDyiYV1M2FbSSwa15O-DAtzvAxOG-z1nUGl5bNSoGCn26kEgb2wGFqnBwbGnbQaPyS_Dm-m-k5HGrzp-kJunI2KyJMjfkWRojrxffvJc3A53_lzM7J88F-7CuyCXAhat0a2N4sn1B5rXvB5s_N0_HNdLGGQ-TngN__p-DlQxyf_Mc6nkBqOtt3LmXgoHaxtPaJmfih_gPxlNas9O4AqtX3X3GhrFMud7syRIhTwLxUhWU2l5_w-8NFqY6AUAAA

To reproduce the problem:

1. Click "Add row" and dismiss the alert dialog.
2. Click "Trigger Row 1" to display the same alert dialog. This works because of the saved component ref.
3. Click "Add row" again and dismiss the alert dialog.
4. Click "Trigger Row 1" again. Nothing happens this time because Svelte set the component's ref to null in the rowRefs registry object. Check out the $inspect traces in the console to confirm.

Note that making the rowRefs object non-reactive works around the issue, but then Svelte complains about the non-reactive binding.

Logs

System Info

System:
    OS: macOS 26.3.1
    CPU: (12) arm64 Apple M2 Pro
    Memory: 891.05 MB / 32.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 22.17.1 - /Users/braedenpartridge/projects/fwd/.gradle/nodejs/node-v22.17.1-darwin-arm64/bin/node
    npm: 10.9.2 - /Users/braedenpartridge/projects/fwd/.gradle/nodejs/node-v22.17.1-darwin-arm64/bin/npm
    pnpm: 10.13.1 - /Users/braedenpartridge/projects/fwd/.gradle/pnpm/pnpm-v10.13.1/bin/pnpm
  Browsers:
    Chrome: 147.0.7727.116
    Edge: 147.0.3912.86
    Firefox: 148.0
    Safari: 26.3.1
  npmPackages:
    svelte: 5.55.5 => 5.55.5

Severity

annoyance