I don’t think it’s a KDE issue. It sounds like you are missing the correct firmware, just check the output of dmesg and it will mention it at some place if that’s the case.
Hi - if it’s not a firmware issue as @jsalatas said, then it sounds to me like a hardware problem in either your device’s Wi-Fi module itself, or some circuitry that’s providing power to that module.
I haven’t had that exact problem on laptops before, but I have had it on a desktop - I was able to reboot and fiddle with hard resets (pulling the power cord) and keep it going for a while, but eventually had to solve it by replacing the wireless card.
For a laptop, it might be worth checking around online - including at your distribution’s forums: https://discussion.fedoraproject.org/ - to see if your device has any specific kernel modules, firmware updates, or settings (like disabling power-saving modes) that are needed for it to function well on Linux. Some laptop manufacturers have historically used non-standard wireless hardware that isn’t always well-supported by the upstream Linux kernel.