I don't think relayd will help here. The LAN and wifi clients are on the same RUT955 router. Looking at the IP links:
root@Teltonika-RUT955:~# ip link show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel master br-lan state UP mode DEFAULT group default qlen 1000
link/ether 00:1e:42:19:d7:53 brd ff:ff:ff:ff:ff:ff
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP mode DEFAULT group default qlen 1000
link/ether 00:1e:42:19:d7:54 brd ff:ff:ff:ff:ff:ff
4: ip6tnl0@NONE: <NOARP> mtu 1452 qdisc noop state DOWN mode DEFAULT group default
link/tunnel6 :: brd ::
5: ifb0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 32
link/ether b6:5a:79:79:9b:cb brd ff:ff:ff:ff:ff:ff
6: ifb1: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 32
link/ether 22:d5:c6:32:f3:83 brd ff:ff:ff:ff:ff:ff
7: gre0@NONE: <NOARP> mtu 1476 qdisc noop state DOWN mode DEFAULT group default
link/gre 0.0.0.0 brd 0.0.0.0
8: gretap0@NONE: <BROADCAST,MULTICAST> mtu 1462 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff
10: wwan0: <BROADCAST,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UNKNOWN mode DEFAULT group default qlen 1000
link/ether 82:69:84:90:35:3b brd ff:ff:ff:ff:ff:ff
91: br-lan: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default
link/ether 00:1e:42:19:d7:53 brd ff:ff:ff:ff:ff:ff
125: tun_c_Emizon: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UNKNOWN mode DEFAULT group default qlen 100
link/none
126: tun_c_Torguard: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UNKNOWN mode DEFAULT group default qlen 100
link/none
141: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq master br-lan state UP mode DEFAULT group default qlen 1000
link/ether 00:1e:42:19:d7:55 brd ff:ff:ff:ff:ff:ff
Both wlan0 and eth0 are connected to the br-lan bridge, so it should work. But it doesn't.