If it is a FreeSync monitor (or GSync, but you have a Radeon in that system information so I'm assuming FreeSync if applicable), the monitor manufacturer may have the FreeSync mode locked to a specific range of refresh frequency, and if that range and what the game outputs and what the monitor will really do don't all match up, you'll have 1-2s blackouts periodically as they fall out of sync. This is considerably more common with FreeSync/Gsync and 1440p144 both enabled.

If that is what's happening, your solutions there are either to disable FreeSync entirely, lock video to a refresh rate in a 'safe' range, or edit your monitor's advertised information such that it will advertise a more appropriate range for FreeSync. (The last one is annoying to do, plus will 100% violate your warranty and also potentially damage your monitor if you overwrite the wrong things. I'd consider it a last resort.)

Or just lock it at 60hz and live with it, which is probably the easiest fix of all.

Another possible cause of signal drop is a bad monitor cable... or a connection with insufficient throughput. DisplayPort seems to work better for 1440p144, where HDMI 2.0 will generally work, and Dual-link DVI is (unfortunately) hit or miss on some monitors I've encountered; usually that presents as a complete failure to output graphics at all, but I've seen it cause signal drops in a few cases. It's a lot less likely, but at least "buy a DisplayPort cable" is not the most inconvenient possible fix here.