That is normal. MediaTek Preloader is a "volatile" mode. It only stays active for 5-10 seconds before rebooting the phone. You must launch SP Flash Tool or Maui META immediately after connecting.
With the shift to 64-bit (x64) architectures in modern PCs (Windows 10, 11, and Server), finding a compatible, stable, and functioning driver has become a nightmare. The "top" drivers are not always the newest; they are the ones that bypass Microsoft’s Driver Signature Enforcement (DSE) and correctly handle MediaTek’s proprietary Preloader and DA (Download Agent) modes. mtk usb serial port driver x64 top
is often described as the "bridge" that allows a PC to talk to the "brain" of a MediaTek-powered smartphone. That is normal