Bluetooth internet sharing on first connected mobile device is not working

Please advise solution, Bluetooth internet sharing on first mobile device is not working on all MacBooks, when you connect 2nd device then 2nd device get access of internet and first still remains same, when u discontent 1st while keeping 2nd connected and connect again it works on both device.

How to solve this and why its built in fault on all MacBooks that i checked. thanks.