I wonder how Windows Bitlocker and other similar software works. I know they differ in terms of security level as some software does not fully encrypt locked files, but I'm speaking of unauthorized remote access. Do they also protect against remote access even after the password is entered and the current state is unlocked?
Bitlocker offers transparent de-/encryption of volumes.
Once the system is booted and the drives are unlocked the system works as if Bitlocker would not exist. Only the regular permission system of e.g. NTFS are then active.
As a system can only be accessed remotely if it is up and running Bitlocker would not offer any additional security assuming that you don't have any volumes that are still locked.
Bitlocker could only help in case the system is dual boot and the Bitlocker protected system is the one that is currently not booted.