Ouch - watch the video at 0.25x playback speed. It looks more like an attempt to wrench that poor riser out of the slot at all sorts of nasty angles. It was hardly going to fall out on its own, so I don't understand the problem. You can use it - the video clearly shows what a nice snug fit it is. It's a riser cable, there is no load on it at all. Also, why pull it out by the cable? I feel really sorry for your hardware.
If you've shared that video with ASUS, I'm amazed that they replaced your motherboard even once, let alone three times. Seems like an ASUS endorsement to me.
Z690 Hero, 12900K, BIOS 3701, MEI 2407.6.1.0, ME Firmware 16.1.32.2473, 7000X Case, RM1000x PSU, ASUS TUF OC 3090TI, 2 x 16GB Corsair RAM @ 5200MHz, Windows 11 Pro 23H2, Corsair H150i Elite AIO, 4x Corsair RGB fans, 3x M.2 NVME drives, 2x SATA SSDs, 2x SATA HDs.