HD7544:

Supply the following if possible:

• Device problem occurs on
• Software versions of OpenWrt/LEDE release, packages, etc.
• Steps to reproduce

I've noticed this across several devices: WRT1900ACv2, TP-Link WDR-3600 and RT-N13U so far. After creating a switch VLAN and assigning it an interface, DHCP stops working if interface name does not start with an alpha character. Naming an interface with the VLAN number (or any number causes this breakage). Only way to to recover is to manually assign an IP address in subnet and rename the interface to something like LAN[VLAN_ID].

Once this is done, all functions as it should.