While older Qlik Sense Enterprise on Windows versions are lenient on the formatting used for the host allow list in the virtual proxy configuration, the February 2022 edition is the first which strict checking.
A former successful request will now be translated into a 400 bad request. In the Proxy_Audit logs, you will find that the hostname calling the server is not present in the allowed list.
In some cases, this will even happen when the entry is on the list due to misformatted entries in the host allow list, which causes the entire list to not be fully loaded.
Remove additional characters in front of the host allow list entries.
Cause
From this version, stricter checking has been implemented due to a security issue found with QB-7782. No longer is it permitted to use .(dot) or *. (star dot) in front of a domain name. This will lead to a 400 bad requests.