MacBook Air M1 chips - Bluetooth 5.0 is not backward compatible

I bought a bluetooth mouse, which is not Bluetooth 5.0. I tried to connect it with my MacBook Air, but I found that it cannot be searched and connected by Mac. I tested my mouse in another devices (some are Bluetooth 5.0 while some are lower version), like Window / Ipad Air 2 / My mobile phone. My mouse works on these devices. I also tested other bluetooth devices are not Bluetooth 5.0, all of them cannot be searched and connected by my Mac.

It is unacceptable that new Mac products' built-in Bluetooth 5.0 are not backward compatible, which violates Bluetooth 5.0 basic function. Is there any way to do in my Mac's setting or will you apply a fix in the coming System Update?

Thanks.