[B650e Taichi] Black screens, no internet, M2 bug

Hello,

Since I've bought the motherboard, I keep having a lot of problems. They were all manageable at some degree but today I seem to have run into about all of them. After 8 hours of trials, I'm coming here for help.

Components :
MB : ASRock Taichi B650e
CPU : AMD Ryzen 9 7900X
GPU : Gigabyte GeForce RTX 4070 Ti Eagle OC
RAM : G.Skill Trident Z5 Neo, 2x32GB, 6000 MHz, DDR5
PSU : Corsair HX1000
OS : Windows 10 Home
SSD OLD : Gigabyte Aorus NVMe Gen4 - 2TB
SSD NEW : Crucial T700 NVMe Gen5 - 2TB

Situation : Today, I wanted to switch my old SSD from M2_1 to M2_2 and install the new SSD into M2_1. I wanted to install a new OS on the new SSD and use the old SSD to store files such as games, music, etc. I've never been able to make it work.

First problem : 9 out of 10 times when I start / reboot / restart the computer, etc., the computer starts normally except I have no display either from HDMI and / or DP in the GPU nor do I have anything coming out of HDMI in MB. Otherwise, the computer seems to start correctly (I know I can enter BIOS because Debug shows code A6 or let it start the OS and see the temperature which is around 40-65 - this is what is shown on Debug).

Second problem : When I place NEW SSD on M2_1 and OLD SSD on M2_2 or M2_3, only M2_1 is visible in BIOS. As there is no OS on it, the computer goes automatically in BIOS even if I don't press F2. When OLD SSD is on M2_1, NEW SSD in M2_2 or M2_3 isn't visible either in BIOS (under NVMe configuration).

Third problem : When I let the machine boot the OS, I don't have any internet access any more. Both KILLER 2.5G and KILLER Wi-Fi are "not present" as per Windows in Device Manager. If I click "show hidden devices", both KILLER appears (3 actually, KILLER Wi-Fi is there twice for some reason I don't know about) but there are greyed out and when I enter "proprieties" I can see they are "not present".

What I did already :
For the M2 drive :
- Tried all possible configuration of SSDs.
- Cleared CMOS several times.
- Updated MB to BIOS 3.06 from 1.28.
- Enabled / disabled CSM
- Enabled / disabled Fast Boot

For the black screens :
- Resited the GPU several times.
- Booting without GPU (HDMI in MB).
- Removing DP cable from GPU when starting the machine, plugging it after the boot is complete.

The only thing that's working is that I must shut off the computer, switch off PSU, remove alimentation cable, wait for 10-20mn, hope that I have no black screen. I've been doing this since the beginning and it works because I always cut power completely off of my machine every night (plug off the wall) and re-plug every morning. I used to have a lot of "CPU stuck at 0.52 GHz" if I didn't enter BIOS at startup and chose "save and exit" for the MB to start scanning the RAM all over again (Debug code 15). I found that removing PROCHOT throttling was effective in removing the problem.

So I, in order to make my computer work again, I must :
1 : Find how to avoid my computer showing only a black screen at startup.
2 : Make internet work again.
3 : Find how to make 1 M2 Gen 5 and 1 M2 Gen 4 work together.

Any help to provide that I could try?

Hello, this morning I thought I would not try to much because yesterday way emotionaly intense and this is my last week of holidays for the year. I wanted to play some games, telling myself it would be alright after all, even without an Ethernet card in my MB, if my computer showed an image, I could use my cellphone as a external modem but I COULDN'T start my computer without it throttling at 0.52 GHz, EVEN WITHOUT the controller that could be faulty. So, there another problem added into the mix.

Here is what happened yet:

1st startup : Image - No internet - Throttling.
2nd startup : Image - No internet - Throttling.
3rd startup : No image.

I still have no solution and CAN'T use the SSD I bought yesterday, nor did I find a fix for any of my problems that are way worse than they were before. It is still amazing that yesterday evening, I could actually use my computer normally (except no SSD ans internet through cellphone)! It DOES work, it is just so hard for the stars to align or whatever that makes it work...

I am so disappointed in AsRock and my Motherboard. I, of course, can't RMA it, since I'm 50% working from home and next week I will have to fight for my computer to work in order for me to work. I will never buy another AsRock product ever again. I mean, look at the state of this board! Filled with BOTs trying to scam us by posting fake Dubai escort adds... This is ridiculous at a degree I have never seen before, and I have experience with computers both personally (I have been building computers since a good decade - my first was on Win XP) and professionally. I am so disappointed now...