Skinflint found a couple? Cheapest is Acer Nitro 5. If you can wait for delivery, XMG CORE 17 (AMD) is estimated to be delivering in November and 2060+16GB+1TB comes out to under 1300€.
That's a DisplayPort IN connector.
It's so that you can plug a DisplayPort signal from a discrete GPU for then it to be routed through Thunderbolt.
Look at page 21 & 22 in the manual.
All Ryzen CPUs have 24 PCIe lanes.
16 for GPU in either 16x or 8x/8x
4 for NVMe (or 2 SATA)
4 for chipset connection
So you're already using all 24 lanes.
Shown in an image on eBay, there's separate SATA ports, then there's 4 ports with U2_1, U3_1, U3_2 and a fourth that's hard to tell.
And the 3 pin cable is labeled USB_PWR1.
So they simply replaced old flaky USB headers with locking SATA ports.
Pictures of the GD30 show that ASUS really did use SATA ports rewired for USB 3.0 it seems. Guessing them being able to lock and have enough pins.
I wouldn't attach them to actual SATA ports, would do nothing.
You would need to figure out the wiring internally and then rig up some custom SATA/USB adapters, imo too much hassle.
Contact your ISP with all this information?
I had intermittent daily disconnects with 4G, opened a support ticket with them, couple weeks later they made fixes which solved it.
Your ISP has all the tools required to analyze things like this and they would know much more.
My university had a HP logic analyzer from the 90s that I found when I was a student there in 2010 that had been sitting in a closet for ages.
Just for fun, tried updating the operating system to the latest version.
It completely crashed during the update because the century and years were stored separately.
So it freaked out when existing files had somehow gotten a date time of 20110 while the version it was trying to install had a date of 200x since 19/99 had turned to 20/100 and some years on top of that.
Only the upgrade failed, it otherwise worked just fine.