If you use DOH/DOT &/or the kill switch with the VPN connections you're going to have trouble syncing time to NTP as there's no RTC in these devices. The TLS/authentication handshakes won't work properly until then.
Adding NTP IPs will be faster than waiting for a DNS response.
uci -q batch <<- __EOF
set system.@timeserver[0].server='0.openwrt.pool.ntp.org 1.openwrt.pool.ntp.org 2.openwrt.pool.ntp.org 3.openwrt.pool.ntp.org 104.167.241.197 73.239.145.47 142.147.88.111 171.66.97.126'
set system.@timeserver[0].use_dhcp='0'
__EOF
uci commit system
That's my best guess ATM.