but I have another question for you - as I understand it, your game and launcher work correctly on Linux, could you recommend your launch settings? (My game works correctly, but without network access, and the launcher doesn't see the installed WebView2). If it's not too much trouble, as I'm using Windows 10 again
1. You will always have optical errors on the new launcher, as it is not fully compatible with wine, but you can click the buttons "single player" and "multiplayer" without problems.
2. regarding the online issue: install directplay in your wine prefix. Most apps like Lutris or bottles have a settings page for that so you just can install directplay easy.