I use a dell at work and connect the q30 easily (FYI q30 are similar to the q35 without the ldac).
So first off what is the laptop and how old is it.
I basically hit the add Bluetooth or other device, found it, and it connected the q30.
I would say restart the laptop first as sometimes there may be some issues there and restarting should resolve some of that.
Restart the q35 and so that it is fresh and not connected to the phone and eliminate issues there.
If it does not connect, there could be a need to update the BT driver that we found that a lot of folks needed when there was a rush for headphones during covid. I would use the search on the laptop and it should take you there or can give you instructions to how to do that as I do not have that view option while at work…
When it fails does it gives you a message or error or something.