AC6605(V2R6)Some stations turn to offline during roaming

It is obvious that there are many stations offline record on the AC6605 and the offline reason is the station signal strength is lower than the threadhold.
(2)Review the configuration of this site:


The station offline reason is that the AP send the eap packets to the station, but the station does not response the eap packets.
(2) Do the same test with four other PCs(one is the same model of samsung(NP200A4B) and other 3 HP PCs),repeat roam testing serveal times but not find the same problem. The problem is only happened on the specific PC, it is confirmed that the problem related with the PC, there is something wrong the wireless card of the PC.
The quick-kickoff-threshold is too low before, the station would be kick offline when the rssi is lower than the threadhold.
The specific problem about the samsung(NP200A4B) is related with PCself, not related with the AP. There is something wrong with the wireless card of the PC.
Perform the following operations to solve this problem:
1.Changing the quick-kickoff-threshold on the AC6605, it was done yesterday and in the monitor process.
2.The problem about the specific samsung PC can be solved by changing a new wirelesscard.
When adjust the parameter of quick-kickoff-threshold, need to change it step by step, and then test the service.