Hello
If the issue comes and goes, and Bluetooth appears and then disappears, this is most likely a hardware connection issue, such as a loose connection or faulty pin.
Driver or software issues typically do not behave intermittently. It will not hurt to install the Bluetooth driver from the computer manufacturer, along with the chipset driver and BIOS update if necessary. However, I just want to set the expectation that these steps may not resolve the issue.
Could you please share two screenshots?
Open Device Manager > Network adapters and take a screenshot showing everything listed there.
Type msinfo32.exe in the taskbar search, press Enter, and share a screenshot of the System Information window.
Thanks!