Store not update on layout when page change

[kapilpipaliya]

Describe the bug
I am using store in different route and a layout. but when on route store is changed on layout its not updating.

To Reproduce
https://github.com/kapilpipaliya/sapper_store_reproduce

Expected behavior
when page is changed the store value in layout should be changed and layout html should be updated.

[kapilpipaliya]

this is simple example to reproduce error:
https://github.com/kapilpipaliya/sapper_store_reproduce1
see https://github.com/kapilpipaliya/sapper_store_reproduce1/blob/master/src/routes/account/_store.js
when index1 and index2 page is changed store value not change on _layout.

[kapilpipaliya]

I use onMount to update store. and it works! thank you.