It seems some 4090 owners are unaware PSU manafacturers have 12VHPWR connectors available. Here is a list of solutions for you to avoid using the including adapter which is causing problems. PSA :
1x 24 Pin Male to Female Dual PSU Power Supply Cable ATX Motherboard Connector | eBay
CPU 8Pin to Dual PCI-E 6+2Pin Splitter Cable
HP Z600 PSU Main Power 24-Pin to 18-Pin Adapter Cable (30cm) MDY-HP-Z600-24-18
Seasonic made a PSU for people who struggle with cable management | PC Gamer
Power Cord Computer C13 | Power Cable Computer | C13 Power Supply Cables - Power Cable - Aliexpress
Be Quiet! Expands PSU Cables Line Up To All Black Modular Cables
Power Cord Computer C13 | Power Cable Computer | C13 Power Supply Cables - Power Cable - Aliexpress
Power Supply power cable compatibility? : r/pcmasterrace
Power Cord Computer C13 | Power Cable Computer | C13 Power Supply Cables - Power Cable - Aliexpress
Using single GPU cable with branches is wrong ? | Overclock.net
Deltaco Power Supply cable extension 0,5m Black - MaxGaming.com
12VHPWR 2x8 adaptor cable from be quiet : r/nvidia
Ultra compact GaN ATX power supply delivers up to 250 Watts - CNX Software
Amazon.com: EZDIY-FAB PSU Extension Cable Sleeved Custom Mod PC Power Supply Cable, Soft Nylon Braided with Comb Kit 24PIN/8PIN to 6+2Pin/ 8PIN to 4+4PIN-30CM 300MM - White : Electronics
Amazon.com: Fasgear PCI-e 5.0 GPU Power Cable - 70cm 16pin (12+4) 12VHPWR Male to Male Sleeved Cable with Combs, 600W PCIe 5 Power Cable for Geforce RTX 3090Ti 4070 Ti 4080 4090
How to Connect Your PSU Cables to Your Motherboard — Power Supply Cable Guide
Premium Individually Sleeved Type-5 PSU Cables Pro Kit, White/Black
4x SATA Power Splitter Adapter Cable - Computer Power Cables - Internal | Cables | StarTech.com
Sleeved PCIe Gen 5 Splitter Cable
Custom Sleeved Cable for Modular Power Supply – Nouvolo
EU Power Cord 1.5m 1.8m 6FT 250V 16A European Standard Euro Plug Schuko to IEC C13 Power Supply Cable for PC Computer Monitor Epson HP Printer TV - China Power Cord, AC
CORSAIR PREMIUM Psu CABLE Kit - REVIEW - The Best Cable KIT - YouTube
Amazon.com: LINKUP - AVA 30cm PSU Cable Extension Sleeved Custom Mod GPU PC Braided w/Comb Kit | 1 x 24 P (20+4) | 2 x 8 P (4+4) CPU | 2 x 8 P (6+2) GPU Set | 300mm - Green : Electronics
XTIA Modular Cables service – XTIA shop
6' LP4 to 8 Pin PCIe Power Cable Adapter - Computer Power Cables - Internal | Cables | StarTech.com
How to Connect Your PSU Cables to Your Motherboard — Power Supply Cable Guide
Antminer Hydro PSU Cable Power Connection APW11 Power Supply – LYS Shenzhen
RGB PSU Cables | ARGB motherboard power supply cable – PC Gods
Antminer Hydro PSU Cable Power Connection APW11 Power Supply – LYS Shenzhen
PCI-Express Gen5 12-pin power cable looks just like NVIDIA's - VideoCardz.com
Black | White PSU Extension Cables Kit | 30 CM Length – PC Gods
REVOLUTION ATX 3.0 1000 Watt 80 PLUS Gold Fully Modular Power Supply - Products - ENERMAX Technology Corporation