Why does fclose()/instrreset take 120 seconds no matter what I do when using visa object with Keysight VNA?

I am using the instrument control toolbox to control a Keysight PNA. The following code causes matlab to lock up for 120 seconds at fclose(vna) and I can't figure out why. I am able to control the VNA, take measurements, read, etc. Only once I try to use fclose(vna) or instrreset I get a 120 window of nothing from Matlab. I have the latest versions of the instrument control toolbox and Matlab 2018a.

v = instrhwinfo('visa','keysight');
vna = (eval(v.ObjectConstructorName{1}));
fopen(vna);
fclose(vna);

[Faiz Gouri]

MATLAB is waiting for the Keysight drivers to close the connection. You can check Keysight IO monitor logs to see the reason for this delay.