GPIB PCIe card communication with Keithley DMMs and SMUs occasionally freezes also in NI-Max/ No problem with USB-HS+

Hello, while trying to read the buffer of a Keithley DMMs or SMUs (2450 e.g.) many times fast enough the in NI-Max freezes,  no response and needs to be killed in task-manager.  Same happens using .NET in Visual studio. After changing to the USB-HS+ this issue is gone. Is there a solution for that problem to be able to use PCIe-GPIB card? 

NI-MAX 18.5, also latest firmware at Keithleys

Thanks