Hello,
this is not a proper bug report (as I haven’t managed to gather enough information so far), but I wanted to ask if anyone else is having problems with initialization of Blackmagic cards in 2025 builds?
I am running 2025.31550 in a production on a machine that has proven to be stable while using 2023 builds. I am using Blackmagic cards and some days go like this - I start the computer and TD project, check the outputs and notice there is no signal being sent from Blackmagic (even though there should be). In case I try to set Active par (in Video Device Out TOP) to off and back on, TD hangs. After closing TD (by ending its process) and opening it again, all outputs work properly. Once outputs start working, they remain working properly throughout the day.
Apart from this, I have seen also other, possibly unrelated issue. After the hang and restart of TD, outputs aren’t synced to reference (I can visually tell they aren’t locked to the studio infrastructure), even though Blackmagic Desktop Video reports outputs are locked to reference. Unplugging reference and plugging it back in fixes the problem. I have never experienced this problem before (when Desktop Video reported that outputs are locked, they were).
I am not sure what could be causing this behavior. I can’t experiment too much with versions / Blackmagic drivers (I am using 15.0) as I don’t want to break stuff while in the production.
Please let me know in case you have similar problems so we can figure out what could be at the root of these problems. 
Thanks.