i just wanted to post this because i saw that a lot of people had Problems with their RX 5700 XT.
I hope that this helps you find a solution to your Problem and you can fix it.
A little information: i bought my Asus RX 5700 XT one year ago and almost instantly ran into problems with it. Game crashes, Greenscreens, Freezeframe crashes. A lot of Problems. For a year i struggled around with finding a solution and allways blamed myself and the rest of my old hardware, until i recently was finally able to upgrade everything.
Turns out: It was not my old hardware and instead a produktfailure with the heater. The memory heater. The idiot i am i never properly tested it.
1.If you have an Asus RX 5700 xt you should look into it, it is actually a big thing and i blame myself for not finding it earlier.
2. If you have an RX 5700 XT from another producer, like gigabyte or something, look into problems with the heater. i include some links to my specific problem maybe it is the thing you were looking for.