Only runs with threads:null

[Yuman]

v2.4.3-beta2
Starting with threads:null, it rewrites with good-looking thread:{} content and runs on RX 550. But restart fails. Each time before it restarts, I have to set threads:null

[xmrig]

Looks like duplicate #51

[sohosynergy]

I had the same problem until I updated from that beta to version 2.4.5 for AMD. I also have the RX 550.
Here's the relevant part of my config.json:

{
    "algo": "cryptonight",
    "background": false,
    "colors": true,
    "donate-level": 1,
    "log-file": null,
    "print-time": 60,
    "retries": 5,
    "retry-pause": 1,
    "opencl-platform": 1,
    "threads": [
        {
            "index": 0,
            "intensity": 512,
            "worksize": 8,
            "affine_to_cpu": false
        }