Not a fan of Discord, it's a very needlessly intrusive app, and is very resource hungry, for something I only use for comms. That's why I prefer to use my old Teamspeak server, but on clan nights my friends force me to use Discord.

Still, I've never seen or heard of a problem like yours so must be something specific to your install.

Some ideas to try:

As suggested below, I would use the Revo Uninstaller to completely purge the registry and DLLs after uninstalling Discord, and then reinstall it clean.

Disable the Discord overlay. I've had nothing but problems with it, and is very often the cause of these kind of problems: https://www.howtogeek.com/839887/how-to-turn-off-the-discord-overlay/

Discord tries to manage the Windows audio devices itself, and may be trying to use a device that has a bad driver that you're actually not using. Instead of having the input and output device set to default, try manually setting them to the devices you want to use.

Speaking of drivers, your audio device may have a misbehaving driver that Windows handles just fine, but is giving Discord fits. You might be using a Microsoft generic driver that Windows installed. I rarely bother updating audio drivers nowadays, but it's worth checking to see if the mobo manufacturer has an updated driver.

If you're using a USB headset instead of onboard audio, I've seen Discord sometimes have issues with these. Try using onboard audio with a regular analog headset for a while and see if the problem persists, if not, then you may need to find a better driver for the USB headset. Usually you just plug those things in and Windows installs a generic Microsoft driver that usually works well enough, but there might be a better manufacturer's driver.

Redeye: I too run at 1440p, no issues, and I used Discord Sunday night for a clan game.

Hope this helps.

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Rest in Peace Joe Flaherty. SCTV was awesome. I should start rewatching those. The one that stands out in my memory was the episode when Russia was jamming their satellite and most of the show was bad Russian TV series like "Tobor's Tractor" which was the Russian version of "My Mother the Car".