It’s a known issue with Windows - it keeps transmitting sound (either media or a hiss) so that fights how the Q30 does switching.
What I did was ditch Windows, I only use Android and Linux and my Q30 work exactly as I want. I do have to connect to Linux laptop first.
There are other workaround but they are complex, with some pros/cons. What you can do is tell your phone to (conditionally) forward to another number which is a VOIP number and run a VOIP client on your laptop. The PRO for this is if you lose phone signal the call will get you over Wifi. You can search for free VOIP numbers, e.g. USA has Google Voice, UK has Sipgate and there other free services. You need a SIP client on laptop, there are free ones. The CON is this complex.
I have my phone sometimes setup to conditionally if no answer or no signal to forward calls to another number. I have USA and UK free VOIP services. I used to work in a building basement with bad cellular signal so this trick of divert to VOIP and Wifi was a useful knowledge and skill to have.
All geeks knew all of this already of course.