I recently updated my driver from 22.10.3 to versions 23.X.Y, now ReLive now uses 5 times more memory (2GB instead of 400MB). I have installed several different sub-versions of the 23 major version, including the newest 23.4.2, and the issue appears with all of them. Disabling Instant Replay immediately frees all the memory, and restarting it gradually fills up until about 2GB is reached.
Before I didn't have this problem with 22.1.2, 22.5.1 or 22.10.3 - therefore I am assuming the problem lies somewhere in the 23 major version update. Downgrading the driver also fixes this issue again. Unfortunately this isn't really an option for me because Battlefield 1 refuses to start on any 22.X.Y driver with error "Detected AMD Driver Version 0.0.0. The required driver version is 16.20.1025 or later." ever since they migrated it from Origin to EA Desktop...
Just to clarify, because I know this will be brought up: No, I didn't change any settings. ReLive still uses the exact same recording metrics, and the saved file also has the same size.
Replay Settings: 16Mb/s bitrate, 180 seconds, Use RAM
Graphics Card: Radeon RX 5700
Current Driver: 23.4.2
Confirmed working: 22.1.2, 22.5.1, 22.10.3