Since this morning 2025 / 09 / 30 ( GMT+0 ) any development preview I create via shopify theme dev aren’t in sync with code / customizer changes which effectively prevents me doing anything.
Reproduction steps
Be me
Start any dev / CLI preview on any store shopify theme dev
Watch previews randomly switching between or not
displaying any changes you make in code or customizer
Additional Info
This seems like a server side update considering I had my
computer still on from the day before, in fact I was working
with no change in setup just a couple hours before that.
At the time I hadn’t updated my system yet but was on
the latest CLi version, while trying to find a solution I:
Tried downgrading the CLI ( Various )
Tried upgrading the CLI ( 3.85.3 )
Updated my system ( Kubuntu 24.04 )
Updated my runtime ( Bun 1.2.23 )
Logged out / in
Various browser restarts ( Chromium )
( Cache is always off of course )
Prayed to the E-Commerce devil ( The one )
This problem both occurs on the localhost preview
and the dev preview hosted on the store domain.
And to repeat it explicitly, this is not
isolated to a specific store for me.
Additional info
Other people at work & apparently most people - judging
by the lack of any other issues around here bringing this
up - seem to not have that problem.
Which is weird considering how server side this issue looks.
Behavior
The exact faily behavior is that in the customizer I can make changes perfectly fine and code changes are displayed no problem, however in
the preview it switches between various states of code / settings with
each reload. For example I start the preview, go to the customizer and
remove a whole section, I reload my preview and * nothing *, no change.
I reload again & again and sometimes it has the change sometimes it doesn’t, the more changes I make the more it switches.
Fun Fact
I should be on vacation right now.
Btw
Could you maybe fix this editor to not just throw away all of what I’ve written just because I press the category selection ..
the only reason I’m still here is because I managed to copy the render text before it also cleared that.
I think when I forget to use it, I have a similar experience to what you’re describing? You can make changes in the theme customizer, code or visual, and watch it save and display the changes. In my experience, at least while working on an unpublished theme, you’ll even see the changes within your dev preview. However, the next time you spin up shopify theme dev it will overwrite the template json and everything else using local files and you’ll be back to square one.
That’s while running shopify theme dev –theme “your-unpublished-theme”
While working simply in shopify theme dev and doing the same edits, I get even more intermittent results like you’re describing.
If you aren’t using it already, shopify theme dev –theme-editor-sync will reflect the customizer’s changes in your local code.
Those are my similar observations, hopefully it helps!
From digging into this it appears there is a bug on our side which affects caching on theme previews, that we’re currently investigating. I’ll update here when there’s more to share.