Hi devs,
My Sapphire RX 550 4GB works perfectly but 2GB cards are not working.
I wanted to try Hive OS but I saw that RX 550 is not supported yet

When will be?
I am no dev for sure, but if your RX 550 4G works and 2G don't it seem to be simple RAM shortage problem. Check memory requirments for algo that you are using. For example for ETH you need at least 3G for DAG to fit in card memory. Try Cryptonite algo (monero coin) it fit 2G for sure.