Decklink Card Behavior?

I'm using a Decklink 4K Extreme 12G card, although perhaps, this might apply to other cards as well?

My issue is, is that on SOME projects, something occurs after awhile, but not initially, that when I close Resolve, the screen on my second monitor which is connected to the Decklink via HDMI will be solid blue, instead of going dark. The only way I can get this blue screen to revert to the normal standby mode is to launch Resolve again, open a different project where this isn't happening, and then close that project. I'm using DR 18.01, but this issue has been happening with at least 1/3 of my project on all previous Resolve versions I've used as well. My systems is: 3960 Threadripper, 3090 GPU.

I may be incorrect, but I assume that this has something to do with the Decklink card. Is there some setting which I'm unaware of in the effected projects which will stop this annoying behavior?

[Dwaine Maggart]

I'm not sure this would matter, but go into Blackmagic Desktop Video Setup, and on the Video Output tab, set the Default video standard to something that the monitor supports. It defaults to 525i59.94 NTSC and if it was going into that mode when Resolve exited, that might annoy the monitor.