How to enable 2.4GHz

Which VM Hub does not have Wi-Fi enabled on the 2.4GHz band ? 

Hub 5 in Router mode on the current software revision suffers from repeated Wi-Fi and DHCP failures

Try a power off / on of the Hub 5. Failing this a full factory reset.

With the current defective software these are only a temporary fix

Ooo the hub has 2.4GHz enabled it just don't work well.

look to get your own wifi router with 1Gb or 2.5Gb ports and use hub in modem mode