When you delete the last parameter from the query view, the query view doesn't get updated or refreshed and keeps showing the parameter. If you save the query and opened it again, you see that the last parameter is not existent.
This was identified as an issue in Aurea CRM 13.1 and has been fixed in Aurea CRM 13.2. You are advised to download and upgrade to the latest product release to mitigate the issue. Note that you will need access to the Worx portal to download the latest product release. If you don't already have access, please raise a support ticket.
For granting Worx account access, follow the process listed in Request Access or Support for Worx (Aurea Community) Portal - Internal.
If for any reason you can't upgrade to the latest product release, please reach out to your Account Manager by writing an email to email@example.com to evaluate the possibility of acquiring a hotfix. Please note that these requests are assessed on a case-by-case basis after internal assessment.