Am I the only one feeling that it's becoming more and more unlikely to obtain good cards when dueling with LD? I defeated Super Joey each time with a score not less than 3000, and i didn't get one single rare card, same with yugi moto (one rare card!!). It's really frustrating, it was easier before to get good cards, now it's all rubbish
3K assessment is pretty low, although you can get lucky. I had a similar experience with my first Yugi Mutou event (which was his second appearance) but by this last time he appeared, I had obtained enough cards to farm him, Cerberus Farm, and I got 7K assessment regularly.
Just focus your resources on obtaining cards that will help you farm, then invest in your PVP deck. Farming is probably less important if you have money to spend on the game, otherwise, prioritize farming cards over PVP.
Have you messed with the animation settings, i.e. for battery saving?
I remember having to do that manually because I had low battery, maybe your device has done the same automatically to remain online?