I need more information than just wattage.
Should have a brand and model.
Your CPU has a TDP of 140 Watts.
The RTX 3080 can draw a maximum of 350 Watts.
The rest of your system draw power too. RAM, fan, drives.
If you have a 550 watts that is cutting it close. Meaning the PSU will be running at just under it's max capacity and this is only if your PSU is a good model PSU that can give 550 watts.
I would recommend you replace the PSU for a 650 watts from a good brand and model. If the 750 watts is a few dollars more go for a 750. Headroom is good. Especially if the price difference is minimal.
I will wait for that PSU brand and model. If you can take a picture of the voltages information on the PSU in...