Password server connection keeps being rejected by Kee

As per the title, Kee keeps rejecting the connection to the password server because “their security level is too low. [I] must restart the authentication process using higher security”. I don’t really understand what that means, and I didn’t have that problem until some time ago.
I’ve checked the security levels in KeePassRPC options, they’re both to medium. I’ve also checked the used port and the key expiry timer, which are both default values.
Problem is, I don’t know how to actually restart that authentication process. I’m also using Firefox and my problem seems similar to a topic called “Connection Security” from Dec '17 but in the end I don’t know how the topic submitter ended up solving the issue.
Any ideas pls?