If you have free ports on the physical switch, try changing the ports that connect the Esxi that has the ping defect.
I've already connect to another port, on an other switch.
There is two VM's on a first vswitch connected to a first physical switch, a third VM on the second vswitch connected to a second physical switch.
But all the ping to these VMs have the same random time out.
(the VmWare tools have been updated too).
Please draw a schematic from your ESXi Networking (state of vSwitch and port group) or take a picture of its current configuration.
Did you ever check uplink ports on physical switch side? is there any specific security configuration like etherchannel?
And also tell me about your uplink failover policy on vswitch and state of uplinks (Active/Standby)Please mark my comment as the Correct Answer if this solution resolved your problem
Thank you for you advices.
This is a track that I had already exploited, but I followed the recommendations of this article for all network cards.
(I've found this link, by following the different links you gave me).
This is maybe obvious but the switch ports are often with autonegotiation, and the default configuration of the Vmware NICs, is not "auto, Unlike older VmWare versions.
I set "auto" on all the ports of the VmWare host, the management port too (the speed was "100 Mbps", an now the speed is "Giga").
I've do some changements, to my networking too (the main ports of the VmWare host on the same switch).
With this changements it seems better now. I'll see in the days to come.