Code for updating store value doesn't generated if store value actually not used in the component even if it used in other components.
REPL: https://svelte.dev/repl/ebcbacf20ea3402c990c92c7caf81ac6?version=3.10.1
If uncomment store usage in template example start to works correctly.
Should be mentioned that this worked in 3.10.0 as per repl url change
thanks — looking into it