Origin games sometimes won't launch if IPv6 enabled

I recently had trouble launching Origin games, like Apex Legends and Titanfall 2 (Steam edition).
The problem is like: I click a PLAY button in Origin client, the EAC launcher pops-up, after the loading bar reaches the end, no game window will pop-up, but the game process can be found in the Windows task manager. After several minutes, the game process will exit automatically, and the PLAY button in Origin will be clickable again. No error message, no crash report window. But, sometimes the games just can be launched normally.

After contacting EA support again and again with no useful result, I tried to save the Origin client logs (%localappdata%\Origin\Logs\Client_Log.txt) and look into them. Then, I finally found where the problem is.

If I disable IPv6 in the network adapter, start Origin, then I could launch the games successfully. If I re-enable it and restart Origin, then the problem reproduces.

When IPv6 is disabled, two lines will be in the client log at some point launching the game:

Origin::SDK::Lsx::LSX_Handler::extractGameInformationToConnection           11648     OriginSDK Version 10.6.2.7 Connected.
Origin::SDK::Lsx::LSX_Handler::extractGameInformationToConnection           11648     OriginSDK Game Connected: GameName: Apex Legends™, ProductId: Origin.OFR.50.0002694, MultiplayerId: 194908, CommerceProfile:oig-real, Found Matching Entitlement: Yes

I'm using Orange Spain as ISP (with fully functional IPv6 network), Cloudflare as DNS (both IPv4 and IPv6), I don't have any trouble using other programs with IPv6 enabled. I think the problem is either caused by Origin client or Windows 10 2004, I didn't encounter it before upgrading to 2004. (Yes, of course I've tried reinstalling Windows 🙂)

Both successful and failed Apex launching Client_Logs.txt are in the attachments.