Quagga OSPF: routing priority does not work

[dark_puma]

Good day

I have a central site and several branch sites that are connected to it via OpenVPN tunnels. Branch sites can only see the central site, not each other. I have set up dynamic routing with Quagga OSPF. The central site has priority = 255, Branch sites = 1 (the default).  In the calculation of the routing table, one of the branch sites becomes DR, resulting in the routing table gets only this site. Setting routers priority = 0 from web interface does not work, it still remains = 1\. Addition of "IP OSPF PRIORITY = 0" to the branch routers Qagga config solves the problem only until the router reboots or VPN tunnel goes off.
Is there a way to resolve this issue?