I found out that there is a big problem with the rx 5700 xt driver or card itself. When I use two or more monitors, the latencys are really high and cause audio cracks and pops. These latencys are measured with LatencyMon. On versions 20.10.1 or older the latencys are not normal but low enough, that I can't hear any pops or cracks. With Versions like 20.11.1 or newer, I have massive latencys of 25000 (normal is a few hundred). When I only use one monitor it's fine. But when I plug in my second monitor the latencys go insane.
I tested my graphics card in four different Pc's, with the same result. The Vega 64 for example is fine with any driver version. I know that there are some other people suffering from this problem, but after months, I was in contact with a AMD expert, he stopped answering to my mails, so we never solved the problem, although I found the reason.