Optimized build for IPQ40xx devices

Sorry if this is offtopic...
Has anyone ever faced the issue that 5GHz wifi is not coming up / going down on it's own?

I tried deleting wifi config and rebuilding it. Often it's possible activating it when typing "wifi up" into an ssh console. I don't really understand when its working and when not.

Sometimes it's fine on ch 104 sometimes on ch 64. Now its set to ch 52 and not working at all...

Honestly I don't know where I should look for hints. The only pointer I found in dmesg was this here: Ath10k: "Firmware lacks feature flag..."

Maybe someone knows what this might be, or maybe it's fixed in this special rom?

Thanks for any idea.