Error after entering the download password

After updating to version 3.3.75, errors occur when attempting to download files protected by a password. The error message displayed is “Invalid request.” Downloads that do not require a password work without any issues. Furthermore, the problem does not occur when rolling back to version 3.3.72, indicating that the issue was introduced somewhere between versions 3.3.72 and 3.3.75.

In the Download Manager settings, access control is configured for the “Subscriber,” “Editor,” and “Administrator” roles. The error persists even when a member logs in and provides the correct password, or when an administrator logs in and provides the correct password. I am using the WP-Members plugin, which assigns the “Subscriber” role to users upon login.
What could be the cause of this issue?