when will the update for wallet version catalina OS finally come?
There is a new version out, that has support for macOS Catalina. You can read more about it here: https://www.reddit.com/r/reddCoin/comments/gxskjw/reddcoin_rdd_core_wallet_release_v3100rc4_core/.
There will be a final v3.10.0 version soon, but you can already use the rc4 (release candidate) version; that works just fine.
Please install the most recent version - v3.10.3.
Direct download link for macOS: https://download.reddcoin.com/bin/reddcoin-core-3.10.3/reddcoin-3.10.3-osx-signed.dmg.