I have the same issue with my 2200g processor and vega 56 graphics card. Since I also have an audio interface (external sound card; Steinberg UR44) for recording purposes, I managed to eliminate most of my crackling issues, however. First of all, I changed my latency settings from 128 bit to 1024 bit in Logic (maybe this can be done in garage band also). Then I switched to another Browser named "Vivaldi". While watching Youtube, or playing around in Logic, I now had no more sound issues. However, In the Safari Browser everything still crackles like before. I haven't done any more testing to this point, so I don't know, if the latency settings did the trick, or the different browser. I probably have a lot more tweaking to do, but at least it is now useable for my day to day tasks
I hope this helps, I did not find any more solutions by searching different forums and google.