Unplugging and plugging monitor back in while computer is running

Motherboard: GA-Z170N-WIFI

CPU: Skylake 6600k

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I’ve been running 10.12.6 successfully for a while, but I just noticed a strange issue with regards to unplugging my monitor (Dell 2209WA) and plugging it back in while the computer is running. When plugging back in, there is either: no signal, a black screen that glitches out and I can see the cursor, or the screen goes grey with coloured noise. The computer doesn’t freeze, the monitor just doesn’t work until I restart. I'm using the DVI out. Using integrated graphics/ no graphics cards installed.

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Does anyone have an idea of what the problem might be? Thanks.