I ran into the same problem and worked around it by turning the function calls into plain promises like so
https://svelte.dev/playground/1c7393b8c9a5457f8261ec65c33fdf48?version=5.2.8

cnt becomes a dependency of the await block by being read inside init, and that causes the await block to rerun. We likely need to wrap these calls in untrack in legacy mode

@dummdidumm What exactly is this dependency tracking, when does it come up? Function calls haven't been invalidated by dependencies in the past.

Invalidating function calls when deps change causes code like this to break too
In svelte 5:
https://svelte.dev/playground/hello-world?version=5.2.9#H4sIAAAAAAAACm2MwUrEMBRFf-XxVi0tdnBZ04A7_8G4mEnfQDDzEpIXRwn5dwlV3Li7HM65Ffl8I1zxhbwPcA_J7zDQ7oT2EWe8Ok8Z19eK8hW71wHOv9VzjA_5g7x0djln-o_bwEIsGVdU2SYXRRs24knAhsICG5yeDHd2LWzFBYY-hhFqh0YSSUn8Y0_w2G1phtXy98cq6npkTS1RG1aXIhIYAlvv7PtWhxE2fbxMU9OObaIbsajlMLVhnFHoU3CVVKi9tW9ABERgIAEAAA==
In svelte 4:
https://svelte.dev/playground/hello-world?version=4.2.18#H4sIAAAAAAAACm2MwUrEMBRFf-XxVi0tdnBZ04A7_8G4mEnfQDDzEpIXRwn5dwlV3Li7HM65Ffl8I1zxhbwPcA_J7zDQ7oT2EWe8Ok8Z19eK8hW71wHOv9VzjA_5g7x0djln-o_bwEIsGVdU2SYXRRs24knAhsICG5yeDHd2LWzFBYY-hhFqh0YSSUn8Y0_w2G1phtXy98cq6npkTS1RG1aXIhIYAlvv7PtWhxE2fbxMU9OObaIbsajlMLVhnFHoU3CVVKi9tW9ABERgIAEAAA==

cnt becomes a dependency of the await block by being read inside init, and that causes the await block to rerun. We likely need to wrap these calls in untrack in legacy mode

I find this hidden reactivity somewhat counterintuitive, given that we have runes specifically designed for declaring reactive values. Wasn't one of the key selling points of runes that they provide a clearer and more intentional way to define reactivity?