Help fix GPU not detected

[nkkyy]

Hey,
My PCI-E lanes (all of them) provide power but do not detect any GPU I am trying to connect.

Background to the issue:
I was in a middle of a gaming session when suddenly my graphics card's fans speed ramped up to 100% and I got a black screen (PC was still running).
At first I have tried to restart my computer hoping it would resolve this issue but to no avail (same issue occurred).

Fixes I have tried and process of elimination:

• Checked GPU cable connectivity (Monitor to card, and card to PSU)
• Tested with different monitor
• Tested with different GPU
• Tested with different cables (HDMI instead of VGA)
• Tried to re-seat GPU (different lane as well)
• Tried to re-seat RAM (tried with 1 stick as well)
• Tried disconnecting all USB extensions
• Tried to reset CMOS (20 or more times)
• Tried to rebuild my PC outside of the case
• Tried flashing BIOS (after managing to get a POST)
• Tried updating windows (when PC finally booted)

Quick note:
After building my PC back inside of the case, I have tried to switch to a different HDMI cable and connect it to my motherboard.
As I was booting my PC, I have noticed that my PC boots and I have picture.
After booting into windows, I have noticed that my GPU was still acting weird and when I tried to connect the HDMI cable to the GPU, I was still receiving a blank screen.
Eventually I have looked at the Device Manager and saw no GPU besides my Integrated graphics. At that point, I have decided to check the BIOS and saw that there was nothing "connected" to the PCI-E lanes.
Both my RTX 2070 and GTX 750 were working perfectly fine beforehand, and both are "working" but do not provide any picture.

List of specs:
Motherboard: ASUS Z170 MAXIMUS VIII RANGER
CPU: Intel Core I5 - 6600k
GPU: ZOTAC RTX 2070 Mini (2nd GPU: MSI GTX 750 1GB)
RAM: Dual HyperX Fury Black 8gb (16 in total) 2400mhz
Monitor: BENQ xl2411z 144hz (2nd Monitor: some unknown Samsung)
Storage: Intel 660p series M.2 SSD 512gb
PSU: Sentey Blade 750w 80+ bronze non modular

OS: Windows 10 Pro 64bit version 21H1

BIOS: Version 3802

I have only 2 questions which are,
Is there any fix I did not try and should?
I am intending to upgrade my rig anyways in the near future so, should I keep my RTX 2070 and risk creating a shortage of some kind (can not test in another PC)?
Thank you in advance!

[RAS_3885]

When you re-built the computer outside the case did that include removing and re-installing the CPU?

[nkkyy]

1 hour ago, RAS_3885 said:

When you re-built the computer outside the case did that include removing and re-installing the CPU?

Yes I did re-install the CPU. I let it lay on my desk for a couple of minutes as well. I have inspected the socket and the pins incase some were damaged or bent.
As I insured everything was fine, I re-installed the CPU.

[nkkyy]

Today, I managed to boot my PC and apparently my card is now being detected in Device Manager (obviously BIOS as well). 
Now the problem is that I do not get any video output to my monitor.

[nkkyy]

Currently my GPU is hidden in Device Manager and is grayed out (As seen in the 1st pic).

I am able to get the monitor to display a picture only if I connect my HDMI cable to the motherboard (If I connect it to the GPU, I get no signal comment from my monitor).
I have tested both GPU's with 3 different types of cables (HDMI, VGA, DVI-D) and none worked (2nd pic displays a blank monitor when I switch to DVI-D mode).

I did also decide to rebuild my oldest PC to try and replicate this issue (H81M-Plus and i5 - 4460), though no signal was sent even with the iGPU of that system.