Hi,
I have a similar problem.
ESXI 6.5 on Gen8 with two NICs :
I use this : (Updated) HPE-ESXi-6.5.0-OS-Release-iso-650.9.6.0.28 (Hewlett Packard Enterprise)
[root@ESXI2:~] esxcfg-nics -l
Name PCI Driver Link Speed Duplex MAC Address MTU Description
vmnic0 0000:03:00.0 tg3 Up 1000Mbps Full a0:b3:cc:df:1c:9f 1500 Broadcom Corporation NetXtreme BCM5723 Gigabit Ethernet
vmnic1 0000:02:00.0 r8168 Up 1000Mbps Full 00:e0:4c:80:1a:50 9000 Realtek Semiconductor Co., Ltd. RTL8111/8168 PCI Express Gigabit Ethernet controller
When i set MTU 9000 on the Network interface on the guest. The guest reboot...
I analysed esxi logs, but i don't see error.
I created vswitch and port group after, at MTU 9000.
Any ideas ?