just found out there is a 9.1 version of the pulse client (from may) and in the release note:
=> PRS-369889 Summary: Authentication with Host Checker verification fails on Kernel 4.18.0
and indeed, it seems ok when I tested it.
I have just downloaded and installed the 9.0R4(943), and it does not work on 4.18 yet!
Where can we download the 9.1?