That’s a tough spot, especially when a card that was working fine suddenly gets declined. It sounds like the issue might not be with your card, but with how their payment processor is handling recent transactions or updates, which is a common pain point with subscription services.
I moved away from using my main bank cards for services like this a while ago precisely because of these unexpected declines and the hassle of tracking subscriptions. I’ve been using a service called Halocard, and it seem to have fixed it. I generate virtual cards for each merchant, which seems to resolve a lot of these random processing failures.