Vyos loses routes when primary DC goes offline

Hello. We rely on Vyos for VPN services (5.4.156-amd64-vyos). When we bring down the PDC for patching or maintenance, none of the VPN users get routing when they connect. There is a BDC, however vyos doesn’t seem to use it. I’ve inherited the setup, so when I need to do maintenance I need to either at job a reboot of the server or be on-site. This doesn’t work well since most my server maintenance is outside business hours.

Two questions… first, is this a known issue? If so, are workarounds documented somewhere?
Secondly, if I can get to the vyos, what would the commands be to reset the VPN so I don’t have to bounce the server every time?

Thanks.

Hi, the problem absolutely not clear without nodes configuration
Which type VPN are you using? Which routes do you lose? Which failover type ?
How master/backup connected between each other? Which VyOS version?
Is it bare metal is or virtual servers?