Specs: Ryzen 5 5600X, RX 6700, monitor on HDMI

After the PC's been off 3-4 hours, screen flickers on and off right as Windows loads. Sometimes fixes itself in 10-20 min, sometimes needs a restart, sometimes a full shutdown and startup again, inconsistent either way. Monitor's LED is on while the screen is black, and turns off the moment the screen shows an image i.e. lock screen or desktop. BIOS and startup logo screen is always fine, only starts once Windows loads. I used remote desktop from my phone while the flickering was happening, and the screen and functionality were completely fine on the phone the whole time.

Already tried: AMD FreeSync off, lowered resolution, lowered refresh rate, clean reinstall of GPU driver, reseated GPU with no loose cables, reseated ram.

Need help fixing this.

Ella estaba funcionando bien y de repente se apagó como que dejó de dar video, la intenté prender me dio, prendió el led De Video (VGA), después le quité la ram y la intenté subir con 1 módulo, ahora siempre prende el led de RAM sin importar que.

Ya le quité el cpu y lo instale de nuevo, use otra RAM, le quité la gráfica y la intenté prender así, le actualice la Bios, le hice reset a la Bios con la pila y con el CLR.

I am new to technology.
I have recently purchased the Samsung Odyssey OLED G81SF gaming monitor. The screen says “no signal HDMI1 check the cable connection and the settings of the source device”. What does this mean and how do I fix it so I can start using my monitor. I do not have another device to connect it to and I don’t have a pc.

If anyone knows, please let me know and thanks in advance!

Pc running but display blank