Starting on July 7, 2023, we began observing random "Invalid signature" errors when validating app proxy signatures using the method described in the following documentation:
https://shopify.dev/docs/apps/online-store/app-proxies#calculate-a-digital-signature
In these cases, the incoming signature differed from the expected signature only by the last character. For example:
Expected: ...d318
Received: ...d319
Prior to July 7, 2023, these errors did not occur. What could be causing this?
