Sounds like you already completed most steps from the checklist.
If you already tried different cables and monitors and did a clean driver install,
then it might indeed be the cards HDMI port. Which would be an warranty issue.
In this case you should contact your vendor about a replacement card.
Did you install any Windows Updates just before the last shutdown?
(when the HDMI was still working - it could be an issue with Windows Updates)
--- [ CPU: Ryzen 7 3800XT | GPU: ASRock RX 5700XT Challenger Pro 8GB | driver: 24.1.1 ]
--- [ MB: MSI B550-A Pro AGESA 1.2.0.7 | RAM: 2x 16GB 3600-CL16 | chipset: 6.01.25.342 ]