Overwatch intermittent hitching/stutter

[AsylumDemon]

So after two years of trying to troubleshoot the issue myself, and after Blizzard support telling me they can't help after a week of trying, I'm coming here. The issue I'm having is occasionally several times a match (but not every time I play as in if the issue is appearing it will for the time I'm playing but not always the next time I load the game) I'll get this hitching like momentary stutter, where anywhere from around 100ms to a full second the game will pause/freeze before returning to normal. It seems to happen regardless of what is being rendered on screen, and regardless of what programs I have open. When the hitching happens the GPU usage drops to zero. Note that this does not happen with literally any other game I've tried including: Diablo III, StarCraft II, Heroes of the Storm, Tom Clancy's Rainbow Six Siege, Tom Clancy's The Division 1 & 2, Tom Clancy's Ghost Recon: Wildlands, Arma III, Devil May Cry 5, Resident Evil 2 (remake), DOOM, Diablo II: Lord of Destruction, Star Wars Battlefront 2 (classic and remake), Deus Ex: Mankind Divided, Battlefield 4, Battlefield 5, Anno 2070, Star Citizen, Apex Legends, Crysis 3, HITMAN (remake), Project Cars 2, Warhammer 40,000 Space Marine, Quake Champions, Shadow of the Tomb Raider, Rise of the Tomb Raider, Insurgency: Sandstorm, Grand Theft Auto V, Golf With Your Friends, Company of Heroes 1, Company of Heroes 2, Destiny 2, Black Desert Online, Final Fantasy 14, Universe Sandbox, Solar 2, Unreal Tournament (classic), Unreal Tournament 2004, Unreal Tournament III, Unreal Tournament (alpha remake), Fortnite, 3DMark, as well as various vr programs/software/games.

 

For details sake, below is a list of what I've tried throughout the two years I've been trying to solve this, from closing various programs to changing settings, drivers, bios, etc. (Using a spoiler to hide the rather long list)

Spoiler

Programs closed include: 
Wallpaper Fusion (and all related), Display Fusion (all .exe's and services related to it), CAM, iCUE (and all related), Discord, Blizzard Launcher, Steam, Plex Media Server (and Plex Tuner Service, Plex Media Server DLNA Service, Plex Update Service), Sound Blaster Control Panel, Nvidia Geforce Experience (and all related), Aorus Engine, RGB Fusion, Advanced System Care (all programs and services related to it), Microsoft Office Click-to-Run, OneDrive, Google Crash Handler, Microsoft OneDriveFile Co-Authoring Executable, Nvidia Container, Oculus Config Utility (and all related), Samsung Magician, Samsung RAPID Mode Service (and all related), Adobe Update Service, Easy Tune Engine Service (and all related), Origin Web Helper Service, Performance Monitor, PubMonitor, Sound Blaster Audio Service, App Center, Graphics Card Engine, Origin, Uplay, Twitch App.

 

Windows settings I've tried changing: 
Windows Defender disabled through registry key, Windows Firewall disabled through registry key, pagefile set to various drives including the SSD which is the C drive which is where both the Blizzard launcher and Overwatch are  installed to, pagefile set to one drive (currently on C drive), three different Windows installs on new fresh partitions with freshly downloaded iso's of Windows 10 on freshly formatted drives.

 

Hardware settings I've tried changing:
CPU overclocking (from 3.0GHz up to 4.1GHz 24h max load stable/underclocking, GPU overclocking/underclocking, memory using XMP profile (causes BSOD), memory set to 2933MHz (also causes BSOD even with proper CAS timings and voltage settings), memory set to default bios settings, five separate motherboard BIOS revisions including the latest, unplugging literally everything from all USB ports and leaving only the mouse and keyboard plugged in, 
turning on/off the turbo boost feature, reseating GPU, reseating memory, reseating cpu, reseating SSD power and SATA cables, turning off CPU green settings.

 

Software drivers/versions I've tried changing:
Intel NIC drivers and software, Killer NIC drivers and software, GPU drivers (5 different versions) and software, chipset drivers and software. 

 

Overwatch settings I've tried changing:
Max graphics settings, lowest graphics settings, disable/enable client send/receive rate each separately, repair install, fresh Overwatch install.

 

Internet related changes:
Different NIC's, different driver versions, different DNS servers (ISP and Google DNS), different router firmware versions, CAT 5e/CAT 6 cables (all wired no wireless being used), having my ISP Cox Communications run numerous deep scans on my network both in the home and the local node including replacing an entire optical fiber cable which took 4 weeks due to needing a construction permit from the city, different routers, different modems.

 

What I've looked for through monitoring software/hardware and/or task manager:
GPU Usage Drops, GPU overheating, CPU overheating, RAM overheating, RAM usage, CPU usage, GPU usage, GPU Texture usage, GPU clock speed drops, PSU voltages (all well within normal, so much so that I was surprised).

 

Blizzard Tech Support changes:
Checking for CPU clock speed drops, doing a WinMTR, running a memtest86 test run throughout the night (which found no errors), checking for CPU overheating, client limit server send rate on/off, CTRL + Shift + N to bring up the netgraph and send a screenshot (attached to the post), checking for GPU usage drops.

 

Things I cannot try:
Trying a different CPU, motherboard, SSD, or RAM because I don't have any others to try swapping.

I've been working with computers at an enthusiast level for about 17-18 years now and I'm honestly stumped with this one. Anyone up to the challenge of helping me figure out what the hell's going on? I work full time and am beginning to get ready to move in three months so I won't be able to try every suggestion out that day but I will as soon as I can. Any help would be greatly appreciated as I love this game but this issue is keeping me from thoroughly enjoying it.

 

System specs (that are important) are:
CPU: AMD Ryzen 7 1700 (at stock atm)

Cooler: NZXT Kraken X62
Mobo: Gigabyte AX370 Gaming 5

GPU: Gigabyte GTX 1080 TI

RAM: 32GB Corsair Vengeance RGB White 3000MHz

SSD: Samsung 850 EVO 1TB
HDD: 37TB over 11 drives non-raid

Sound Card: Creative Sound Blaster ZXR

K&B: Corsair K70 RGB Rapidfire & Scimitar Pro RGB

Case: Cooler Master Cosmos II 

Fans: Exhaust: Noctua 140mm 3k rpm Top: 2x 140mm NZXT for AIO Intake: Cougar 120mm (the cheap 4 pack)

Router: Linksys WRT1900AC

Modem: Motorola MB8600