In other words, it suggests that expensive Teltonika routers cannot run two independent DHCP daemons on two different bridges. The workaround is to route all requests to a single DHCP instance, which might be aceptable if one could not configure two independent bridges via the admin interface and enable DHCP on both. Teltonika should either disallow configuring two separate bridges with independent DHCP daemons or, ideally, ensure the (web) configuration translates correctly in the back end. Other competitors are able to do so even for cheap $50 units.
This is fundamental flaw: the web interface allows certain configurations that are not properly supported by backend! It is surprising for a $500 unit. I am really shocked.