The server with ESXI 6 does not see more than 20 USB flash drives, what's the problem?

Question

USB

We use EGAIS, and more than 60 individual entrepreneurs already. To do this, we raise virtual machines on ESXI and install the UTM service on them, connect the rutoken with certificates to the server via active USB hubs and transfer it to the virtual machine. On one server (IBM 3850 M2, ESXI 5.5) there are already 29 virtual machines, respectively, 29+ USB devices in 3 hubs (rutokens, other flash drives). There is also a server, here are the gaps with it:
On the server from USB devices: 18 root tokens in 2 USB hubs, 1 key for some software, kvm, 1 flash drive with esxi itself. The total is 20 flash drives + kvm. The server no longer sees USB devices. I insert a new rutoken - it is not defined in esxi. Reboot didn't help. I inserted both into the hub and directly into the server, front and back. If, for example, you pull out the key and insert the rutoken (it makes no difference in the hub or in place of the key), then the rutoken is seen, but the key stops. Tell me, is this a problem with the settings? ESXI limitations? Or limitations of server hardware? Is it possible to get around by putting a PCI USB controller? Has anyone encountered this? Problem server: Supermicro SYS-6028R-TR, Xeon E5-2620 v3, ESXi 6.0 Build 15018929 (VMware vSphere 6 Hypervisor Licensed for 2 physical CPUs (unlimited cores per CPU)

Answer 1

This is a limitation of the ESXi host itself

You can add up to 20 USB devices to a virtual machine, which is the maximum number of devices supported for a simultaneous connection to one virtual machine. The maximum number of USB devices supported on a single ESXi host for a simultaneous connection to one or more virtual machines is also 20.

Answer 2

you have already been told about the restriction, alternatively use a USB-hub network and the OS will gobble up all the remaining flash drives