Query Parameters Result in Invalid api-signature Message

While using POSTMAN to test the examples in an API document, I discovered that whenever I specified a query parameter in a request, the message

Invalid api-signature

appeared, along with a

400 Bad Request

message.

This problem did not occur when specifying GETs without query parameters or specifying PUTs or POSTs with a JSON body payload. This problem did not occur with path or URL parameters, only with query parameters.

I have searched Stack Overflow and throughout the web to see if there was a reason why, without success.

I am running Postman v11.16, using Chrome Version 128.0.6613.138 (Official Build) (64-bit) on Windows 10 Pro.

Does anyone have an idea why this occurs? Just to be clear, the only difference between a successful request and an unsuccessful one is the addition of a query parameter.