Did you just set the multiplier to x46 and save it with everything else on auto? You're going to need to do a lot of reading before you start adjusting voltages.
Intel Coffee Lake Overclocking Guide – GND-Tech
Intel Temperature Guide | Tom's Hardware Forum
I'm not sure how that board handles voltages but I suggest you read up otherwise you might damage your cpu or other components. High voltages kills chips and every CPU is different as are the motherboards. You might have a chip that can run 4.8ghz on 1.24v but you're going to have to do a lot of testing to figure that out.
If you want to just try 4.8ghz with a manual vcore and everything else auto start at 1.35v and see where it goes. You need good cooling. Air, AIO or custom loop it needs to be able to keep your CPU under 80c sustained at full load ideally during your stress testing. Generally everything above 1.25v and it starts getting exponentially hotter.
Again, third time, read up before you start messing with settings.