Got prompted for a new firmware update earlier - https://www.oppodigital.com/blu-ray-udp-203/blu-ray-udp-203-Support.aspx
It is supposed to fix/resolve these issues:
Comparing to the previous official release version UDP20X-29-1209, the major changes included in this version are:
Resolved an issue where the Home Menu was fixed to a 60 Hz frame rate.
Resolved an HDCP 2.2 failure when connecting to an HDCP 2.2 receiver and an older, non-HDCP 2.2 display.
Resolved a black screen issue with certain UHD titles after resuming playback.
Improved a micro-stuttering issue when outputting UHD, BD, and DVD titles at 24 Hz.
Resolved an SACD playback issue where the player would immediately return to the Home Menu.
Optimized disc loader performance for better disc compatibility and spin speed control.
Resolved an issue where the player could not recognize music files when using Serviio server.
Resolved an issue where the RS-232 command #SRC would not work on the UDP-203.
Pressing and holding the Resolution button on the remote for three seconds will reset the player’s Output Resolution, HDR, Color Space, and Color Depth settings to factory defaults.
Improved the gapless playback feature for audio files.
The Home Menu now supports a wrap-around function.
Improved the over-saturation of colors when using the experimental Strip Metadata feature. Please note that the black level is temporarily fixed to a very low level when enabling the Strip Metadata feature.
All features of the previous firmware are also included in this version."