OK, this is baffling.
I have a Cavium / Brocade / Qlogic 16Gb / 10GbE FCoE CNA Network HBA (BR0110401-38 / RS-1860-2A01).
It has two SFP+ ports and is configured for FCoE, which means it shows as 4 devices (2 NIC and 2 FC) but when I attempt to select one in Host->Manage->Hardware->PCI Devices in order to toggle PCI passthrough, the 4 devices start randomly auto-selecting and deselecting... by themselves! It's like an animation - see the attached .mp4 which I took on my phone.
This occurs on both my hosts (ESXi 6.7U3 on a Supermicro machine, and ESXi 7.0 on a Dell R730) when accessed using Firefox, Chrome or Opera browsers running on Windows 7 & 2012R2 on three different machines.
I've updated the firmware on the HBA to the latest version, as well as all the BIOS/Firmware on the SuperMicro & Dell.
Anyone else come across anything like this???
I agree that these kinds of issues are bizarre, and in most cases, it is related to the vSphere client, so you can try CLI. In ESXi, any changes will be committed to a file called "/etc/vmware/esx.conf", so you can edit this file and put some new tags in it. for your scenario, you need to put a tag like this:
/device/000:11.0/owner = "passthru"
Reboot for the change to take effect
I hope this could be helpful