we develop and run an app that uses the carrier service API to put shipping rates into the checkout. This works nicely (for years). Recently, we experienced super weird behavior with newly created stores.
The description field which we return to Shopify after we get a carrier service api call is not displayed in these new stores. This works without any issue in all older stores.
Here is how it looks in the newly created store:
And that is what normally would be displayed:
We weren't able to find any new configuration in the Shopify Admin to correct that behavior.
So to us it currently seems that recent changes by Shopify caused this. @Shopify please escalate this issue so that devs can have a look at it.
We can provide more detailed info and can help in debug this issue if that helps.